While continuing work unrelated to the X-files, Mulder apparently finds evidence of a giant, flukeworm-like monster, living in the New Jersey sewage system.
TWO MILES OFF THE COAST OF NEW JERSEY
Aboard a Russian ship in the Atlantic Ocean, a sailor walks along the lower decks and finds an overflowing toilet. He reports it to the ship's engineer who assigns a sailor named Dmitri to fix the problem. Later on the ship's lower decks, Dmitri works on removing a blockage that the engineer says must be dealt with before the sewage tanks can be purged. Frustrated by the assignment, Dmitri removes an access panel and is looking inside for the blockage when something grabs him and drags him into the sewage tank, even overwhelming several members of the ship's crew as they struggle to grab hold of Dmitri's legs. The ship's engineer urgently shouts orders to the other crew members to flush the tanks out to sea. The water inside the tank then begins to bubble but reveals no sign of Dmitri.
FEDERAL WIRETAP #5A21147
FBI Special Agent Fox Mulder is disinterestedly conducting wiretap surveillance in a small, darkened room within Washington, D.C.'s Longstreet Motel when he is relieved from the assignment by an Agent Bozoff, who is accompanied to the room by an Agent Brisentine. Leaving the room, Brisentine tells
Mulder about his new assignment; a murder case in Newark, New Jersey, where his contact will be a Detective Norman. Mulder is surprised his reassignment was requested by Assistant Director Walter Skinner.
NEWARK, NEW JERSEY
At a downtown crime scene, Mulder meets up with Detective Norman. Heading to the victim's corpse, the detective leads Mulder into a sewer where he and Mulder make smalltalk about their disgust at their surroundings. Norman then shows Mulder to the body, revealing there is not much evidence. Wandering away, Mulder accepts Norman saying that the front side of the body has largely been eaten away and advises the detective to send the body to the FBI, care of AD Skinner.
At FBI Headquarters, Mulder demands to speak with Skinner, despite Skinner's secretary, Kimberly, claiming Skinner is unavailable. Seeing Skinner from Kimberly's office, a frustrated Mulder criticizes the assignments Skinner has placed him on. Once Skinner welcomes the agent into his own office, Mulder sees that a group of FBI officials are gathered around Skinner's conference table. Mulder immediately adopts a more polite air, explaining his current investigation seemed to concern merely a drugland body dumping, but he also mentions the X-files, at which Skinner strongly reminds him that unit has been closed. Reluctantly, Mulder agrees to continue carrying out the assignments Skinner gives him, including his current investigation.
While Mulder is sitting alone on a bench at night, Agent Scully approaches him. Mulder jokes he may be experiencing violent impulses but Scully jokingly answers that she is armed. Once Scully sits down next to him, Mulder vents his frustrations at the seeming triviality of his assignment, admitting that he has even recently been considering leaving the FBI. Scully insists she could help Mulder out with his current case, reminding him there is a dead body to be examined.
Scully later begins the examination, though the smell of the corpse at first clearly disgusts her. All the while commentating on the examination, she notices a strange tattoo on the victim's right forearm and is shocked to discover – while inspecting the man's internal organs – a form of gray flatworm that she then begins to remove.
In Newark, two sanitation workers begin work in a sewer when one, Craig, is suddenly dragged underwater, repeatedly, and screams in pain. The other man, standing on an overhead catwalk, desperately tries to save Craig, tossing a rope into the water near him. Their efforts eventually succeed and the pained man is pulled out of the water. However, he has a large wound on his back so his co-worker, horrified, speeds away to seek assistance.
MIDDLESEX COUNTY HOSPITAL
SAYREVILLE, NEW JERSEY
A Doctor Zenzola examines Craig, who refers to a strong taste in his mouth – while Mulder enters – so the doctor duly inspects her patient's throat and gives him a piece of gum. The doctor then privately talks with Mulder, informing him the sanitation worker is claiming to have been attacked by something undetermined. Zenzola also mentions the wound on the man's back, referring to it as highly unusual. Mulder then briefly questions the victim, who suspects his attacker was a pet snake, and Zenzola shows Mulder the man's wound. Mulder receives a call from Scully, who tells him of the worm she found. Receiving another call, Mulder at first assumes that his caller is again Scully but it is actually a mysterious man who first notifies Mulder that he has a friend at the FBI and then abruptly ends the call. Mulder agrees to Zenzola releasing her patient but is privately perplexed by the strange call.
FBI NATIONAL ACADEMY
After Mulder arrives in Scully's office, she shows him the flukeworm she found, wordily telling him about its parasitic nature. The pair of agents enlighten their conversation with some jokey banter. Scully then explains that she is left to conclude that the unlikely possibility that the single parasite killed the young victim. Mulder theorizes the wound on the sanitation worker's back could be from the scolex of a gigantic flukeworm. Scully starts to laugh at his theory but stops herself, realizing she had become too caught up in their discussion feeling like "old times." Scully seriously refutes Mulder's theory and he acts pleased that he doesn't have to tell Skinner the murder suspect is "a giant, blood-sucking worm." Having assumed the mysterious call he received earlier was due to Scully having launched a campaign for him, Mulder confronts her about it. She is puzzled about the matter but assures him she would never betray a confidence.
Meanwhile, Craig is in the bathroom of his own home. He tries to get rid of the taste in his mouth using an excessive amount of toothpaste. When he spits the toothpaste out, he is shocked to see blood mixed with it. He later showers but experiences an extreme choking sensation, regurgitating more blood and a flukeworm that slithers down the drain.
SEWAGE PROCESSING PLANT
Mulder interviews Ray, a foreman at the county sewage processing facility, who briefly introduces Mulder to a worker named Charlie. Ray tells Mulder about the plant's workings and Mulder shows him the flukeworm from the body pulled out of the sewer. Ray seems unsurprised at its discovery, remarking virtually anything could have been breeding down in the antiquated sewage system. Outside the plant, Charlie notices something moving inside one of many filtration pools. Panicking, he telephones Ray. In a large darkened area inside the plant, Charlie is joined by Ray and Mulder. Charlie explains he is back-flushing the system and tells of his experience of having seen something. What he saw in the water is revealed to the group once it is caught in a large, transparent pipe. It appears to be a slimy, nearly featureless humanoid creature with a giant scolex mouth - the monstrous Flukeman.
Scully is doing research on her computer, in her office at the FBI Academy, when she notices a tabloid newspaper being slid under her door. She briefly exits her office to see the paper's anonymous deliverer is now gone. Scully later comes across an article that suggests officials now suspect the incident aboard the Russian ship was due to some kind of monster. Learning of this incident for the first time, she returns to her computer and brings up a magnified view of the tattoo she discovered earlier. Scully then answers a call from Mulder, who implies he has found a much larger fluke than the one she previously caught.
MIDDLESEX COUNTY PSYCHIATRIC HOSPITAL
The agents peer into a room of the psychiatric facility where the Flukeman is being held. After Mulder points it out to Scully, she reacts in amazement. Using technical lingo, they remark that the Flukeman shares the flatworms' characteristic of being genderless and that it has aspects of both parasitic and primate physiology. Mulder comments he will apparently have to tell Skinner the murder suspect is indeed a "giant, blood-sucking worm." Scully tells Mulder of her conclusion that the body from the sewer was a Russian engineer, a determination she made after having detected its tattoo spells "Dmitri" in Cyrillic lettering. Mulder is puzzled how she managed to determine that, so she shows him the newspaper article, also implying she believes the paper was left by the same mysterious caller who told Mulder that, within the FBI, he has an ally. She tells him of her hope that he won't decide to quit the FBI.
Later in Skinner's office, Skinner looks through Mulder's field report regarding the Flukeman. Skinner deems the report as being acceptable, which Mulder thinks is a humorously odd reaction to the bizarreness of both the case and the suspect. Skinner clarifies he had his reactions to those in the morning and that the current meeting is to evaluate Mulder's work. Both men argue about how the Flukeman should best be handled, Mulder disputing Skinner's plan of transferring the being to a psychiatric institution. Skinner mentions the Flukeman is now responsible for the deaths of two people, as Craig was found dead – in his own home – due to his injuries. Mulder angrily asserts that, if he and Scully had still been assigned to the X-files, they could have saved the second victim's life. Skinner agrees the case should have been an X-file, implies that he took orders to shut down that unit from someone else and dismisses Mulder.
U.S. Marshals transport the Flukeman, bound to a gurney, into an ambulance which then drives away. The vehicle's driver finds, while driving, that the Flukeman has escaped his bonds, leaving clear slime on the gurney's straps. Moments after investigating with a rifle, the driver screams and his firearm is shot once, noises that can be heard from outside the vehicle, which is parked near a sign for Lake Betty Park. The Flukeman then crawls into one of a pair of public port-a-john lavatories nearby and hides inside the tank.
LAKE BETTY PARK
The public toilets are emptied into a tanker truck, via a suction tube that momentarily becomes blocked.
LAKE BETTY PARK
The park is now a crime scene due to the discovery of the abandoned ambulance. When Mulder arrives, he notices the septage hauler truck as it leaves. Again meeting up with Detective Norman, Mulder is told the only evidence is a dead driver and an escaped prisoner. Mulder advises the being will attempt to head back underground. He answers another call from his mysterious contact, who instructs him success in his current assignment is imperative and that reinstatement of the X-files must be undeniable. After the mystery caller abruptly ends the call, Mulder overhears Norman being contacted by an investigator who reports the discovery of the now-empty toilet. With this information, Mulder realizes the suspect may be on the truck he himself passed.
NEW JERSEY COUNTY
SEWAGE PROCESSING PLANT
Mulder hurriedly arrives back at the processing plant. He again talks with the foreman, Ray, who assures Mulder that the Flukeman will definitely become trapped in the sewage system. After a period of intense waiting near the plant's filtration pools, Mulder receives a call from Scully. She tells Mulder the fluke she caught earlier was one of many the Flukeman has been transmitting through its bite, as its method of reproduction, and that the Flukeman is looking for hosts. Ray relays news to Mulder that something has been spotted in a section of pipe. Using a map of the sewers, Ray shows Mulder the exact location of the sighting, the same place where the first body was found – an overflow system connected to the harbor. Mulder suspects both that the Flukeman entered the sewer system there and that the being is working its way back out to sea.
Mulder and the foreman hurry to the sewer. On Mulder's suggestion, Ray tries to close a metal gate over the overflow pipe, but slips and falls into the water. He is suddenly dragged underwater twice but desperate attempts by Mulder to pull him to safety are eventually successful. Mulder spots the Flukeman climbing into the overflow pipe so he races to close the gate, which agonizingly splits the being in half.
Back in Washington, D.C., Scully again meets with Mulder at their bench. Like before, they share humorous banter before Scully sits down; Mulder warns her he may slightly reek of the sewer but Scully chances sitting next to him anyway. Mulder notifies her about his mysterious contact alleging the importance of his work, although Scully at first mistakes those words as having come from Skinner. Scully lengthily informs Mulder she has determined the Flukeman, capable of spontaneous regeneration like any fluke or flatworm, is actually a human mutated by radiation from the nuclear meltdown at Chernobyl, having come off a decommissioned Russian freighter involved in the disposal of salvage material from that incident.
NEWARK, NEW JERSEY
Deep underground, the Flukeman rejuvenates, opening its eyes and breathing long, rasping breaths.
- This episode has several rare qualities. Because Chris Carter was usually associated with writing episodes which dealt with alien subject matter, Producer Joseph Patrick Finn called this installment "a Carter script, but a bit of a departure for a Carter script." Carter himself termed this "one of our traditional monster shows – although we don't do traditional monsters, obviously." (X-Files Confidential, p. 92)
- The genesis of this outing was somewhat revolting. Chris Carter admitted, "'The Host' actually came to me in kind of a very disgusting way." ("Chris Carter Talks About Season Two: The Host", TXF Season 2 DVD special features) The episode was inspired by him closely observing worms that his dog had and recently having read a story about Chernobyl and the extinction of species. "I [...] somehow synthesized all that information," stated Carter, "and put it together, coming up with [this episode]." (The Complete X-Files: Behind the Series, the Myths and the Movies, p. 55)
- Writing team Glen Morgan and James Wong, who had adopted a trademark of writing straight horror episodes in the first season of The X-Files, pushed Chris Carter into wanting to make this episode creepy and scary. (The Complete X-Files: Behind the Series, the Myths and the Movies, p. 55)
- Mulder's frustration with the FBI was inspired by emotions Chris Carter was meanwhile feeling. He related, "I was in a funk when I wrote that episode, actually. We were coming back from hiatus and I was trying to find something more interesting than just the Flukeman. I was irritated at the time, and I brought my irritation to Mulder's attitude." (X-Files Confidential, p. 92)
- Chris Carter conducted some research as to how to depict the Newark sewer system, before deciding to make it brick and extremely aged. Carter explained, "My father actually was a construction worker who put in sewer lines and storm drains for a living, so he was a resource for me, telling me how these things were built, how the catwalks looked." ("Chris Carter Talks About Season Two: The Host", TXF Season 2 DVD special features)
- One scene that was the subject of much deliberation was the one in which the sanitation worker coughs up a flukeworm. This was the subject of one of the biggest arguments between the producers of The X-Files and the Fox network during the first two seasons of the show. Fox's broadcast standards department wanted to cut the scene but Chris Carter fought to keep it, warning the network executives, "If you cut this out, you're going to ruin the episode." (The Truth Is Out There: The Official Guide to The X-Files, pp. 26-27 & 165)
- The engine room in this episode's teaser sequence was briefly considered to be filmed aboard a real freighter. However, it was discovered that no suitable crafts were in port and/or available to The X-Files' production team. Used instead was Port Mann Hydro Substation, at 14115 King Road, Surrey. The sewage treatment plant herein was represented at Iona Island Causeway in Richmond. The medical examination room made use of 1195 Richards Street, near False Creek, and another filming location was False Creek Seawall, near Anderson's Restaurant. (X Marks the Spot (On Location with The X-Files), pp. 55, 56 & 54)
- Producer/Director Daniel Sackheim was asked to helm this episode by Chris Carter. Sackheim later reflected, "I got a call from Chris Carter, saying that he wanted me to direct one of the early episodes, second season, and he said that the premise of it was about a half-man, half-worm. And I told my agent and my agent said [scoffing], 'If that's what they're doing, the show's not long for television, so maybe you should think of doing something else.' So, I guess he was wrong." ("The Truth About Season Two", TXF Season 2 DVD special features)
- The creative staff took this episode's production in their stride, even though it involved depicting the Flukeman, a Russian freighter and multiple sewers. "Sure, it was hard," acknowledged R.W. Goodwin, "but in the end we did it. There was none of the panic or disbelief that was there the first year." (X-Files Confidential, p. 83)
- Production Designer Graeme Murray was tasked with constructing a set to represent the Newark sewers. "We actually created that entire sewer set on stage," recollected Chris Carter, "complete with water tanks and running water." ("Chris Carter Talks About Season Two: The Host", TXF Season 2 DVD special features) Joseph Patrick Finn added, "On one of our stages we have a pit, which is about ten feet deep, sixteen by sixteen wide. He [Murray] basically built two sewers, with one main sewer that he renovated to a central area." (X-Files Confidential, p. 92)
- Filming in an actual sewage plant was challenging for the shooting company. Reported Joseph Patrick Finn, "It was also a hot summer day – about ninety degrees – and it was a pretty difficult and smelly day for the cast and crew." (X-Files Confidential, p. 92) Given the foul-smelling location, the warm weather and a 12 noon crew call, crew members were granted the option of taking the day off or wearing special breathing equipment (bought by the production department at enormous cost) which filtered out the most putrid odours. Despite the proposition of a day off, the entire crew reported for work that day, the most common concern being the distance between the sedimentation tanks and the catering truck. As it turned out, the catering vehicle was parked as far away, and upwind, as the region's geography would allow. This was clearly insufficient for some crew members. After lunch that day, a vomiting session took place with multiple production staffers, beside a far fence on the perimeter of the sewage plant. Later, Key Grip Al Campbell remembered, "Whenever I began to feel queasy, I'd visit the primary sedimentation tank – the place where the raw, untreated sewage came in. A couple of minutes of that and I'd go back to whatever I was doing, feeling relieved and grateful that nothing else was as bad as where I'd just been." Shortly before midnight, the plant's emergency alarm system sounded, which resulted in a brief delay from the filming. The production team were informed that the timing of this alarm, sounding during the location shoot, was coincidental and that the production crew was not responsible. (X Marks the Spot (On Location with The X-Files), p. 56)
- Even though David Duchovny and Darin Morgan appeared together in one of the sewer scenes, Morgan relieved himself in the water. "I figured Duchovny would never find out," noted Morgan. ("The Truth About Season Two", TXF Season 2 DVD special features)
- During production on this installment, a situation arose involving a man who was sub-letting a building at 1195 Richards Street and personnel assigned to The X-Files. The production unit had made a contractual agreement with the lessor of the property to erect a set, in order to represent the medical examination room in this episode. "We were scheduled to film on the False Creek seawall near Anderson's Restaurant and needed another location nearby to complete our day's filming," offered Location Manager Todd Pittson. The construction and set decoration departments required two days to complete the set for the medical room. "Filming [there] was completed without incident and sets folded and removed," recorded Pittson. The next morning, though, the sub-lessee began insisting the production unit had stolen some video lottery terminals which had been in the building. Eventually, it turned out the man was somewhat mentally unstable and no stranger to Ontario's criminal justice system. "I believe that [he] [...] eventually realized that with our knowledge of his criminal background came certain defeat," Pittson hypothesized, "and the harassment soon ceased." (X Marks the Spot (On Location with The X-Files), pp. 54-57)
- Joseph Patrick Finn considered this episode to have been groundbreaking in the amount to which it reveals such lifeforms as the Flukeman and flukeworms. "Although we had done some creature parts the first year, this time we got to see more of the creatures than we had before," Finn observed. "That was a departure." (X-Files Confidential, p. 92)
- This episode features the first appearance of the mysterious character known simply as "X". However, his face is not shown until his next appearance, the later Season 2 episode "Sleepless".
- Chris Carter was pleased with the depictions of the Flukeman and the Newark sewage system. Addressing the latter first, he remarked, "It was wonderfully done by our production designer, Graeme Murray, and the action scenes in it play so creepy and real that you never, ever doubt that Mulder isn't going underwater and taking a big mouthful of sewage [....] I actually wanted to see less of [the Flukeman] [...] in the show than we did; it just so happens that some of the angles and the lighting showed more of him than I wanted to see. But I think that's what was creepy too, as you never got a perfect look at him until the very end." ("Chris Carter Talks About Season Two: The Host", TXF Season 2 DVD special features) Carter cited another highlight as being the fact Skinner, a man Mulder has herewith never considered an ally, gives him a case which is essentially an X-file. "It's an interesting establishing of the relationship between them," Carter said. (X-Files Confidential, p. 92)
- Daniel Sackheim also thoroughly approved of this outing. "It's classic Chris Carter," he opined. "I remember when I read the script I said, 'You've got to be kidding me.' It has elements of Creature from the Black Lagoon. It's what makes the show the show. Nobody else would attempt to do something like that. It has to be done with a fine touch so that you wouldn't be laughed off the screen. The concept is fairly preposterous, and the subject matter is a little stomach-churning. I think he wrote a terrific script, and I would like to think it was handled adeptly." Sackheim pointed to the scene where a man coughs up a fluke as "such a testament to what is great about the writing of the show: [...] [attention-grabbing] events that don't require any dialogue." (X-Files Confidential, pp. 92-93)
- The same scene likewise delighted James Wong. "I will never forget that toothpaste scene," he proclaimed. "I thought that was the grossest piece of television ever put on the air, so that was cool." (X-Files Confidential, p. 93)
- In common with Chris Carter, both Joseph Patrick Finn and Todd Pittson were happy with the set for the sewers of this episode. (X-Files Confidential, p. 92; X Marks the Spot (On Location with The X-Files), p. 55) Finn enthused, "Graeme Murray did a great job building those sewers. It was very cleverly designed." (X-Files Confidential, p. 92) Pittson considered the area "a truly wonderful setpiece." (X Marks the Spot (On Location with The X-Files), p. 55)
- Chris Carter once called this "one of the, I think, ever-popular episodes on the show." ("Chris Carter Talks About Season Two: The Host", TXF Season 2 DVD special features) He specified, "'The Host' has become a real popular episode." (X-Files Confidential, p. 92) Frank Spotnitz agreed, "There's something very visceral about this flukeworm and this Flukeman. It really captured people's imaginations and that was one of the big themes of the show, was finding things that were scary and real. And everyone seemed to be able to imagine, you know, for instance being attacked in a porta-potty, something coming out of your toilet. I think it speaks to deep fears – you know, urban myths people have heard their whole lives about, you know, snakes coming out of toilets or being attacked in vulnerable places, like a bathroom."
- This episode achieved a Nielsen household rating of 9.8, with an audience share of 17. This means that roughly 9.8 percent of all television-equipped households, and 17 percent of households watching television, were tuned in to the episode. It was viewed by 9.3 million households. (The Truth Is Out There: The Official Guide to The X-Files, p. 249)
- In 1995, The X-Files Magazine (The X-Files Magazine Volume 1, Issue 2, p. 32) speculated edits to this installment were probable when and if the episode was shown on BBC later that year. This prediction was made due to the graphic content in this outing, such as the autopsy scene and the Flukeman. The episode ultimately did air on BBC 2, on 4 September 1995.
- Cinefantastique (Vol. 26/27, No. 6/1, pp. 58 & 61) gave this episode 2 and a half out of 4 stars. The magazine commented, "The series' most graphically gruesome episode so far, the body parts and wriggly flukes are a real kick, but numerous scenes of interaction between Mulder and Scully, and Mulder and Skinner, provide also for excellent characterization. Ultimately, 'The Host' is a letdown, because the pitiable Flukeman is, after all, obviously a man in a suit, and Scully's 'scientific' explanation ventures far beyond extreme possibilities into a ridiculous impossibility. The scene where a lone federal marshal takes charge of the Flukeman slips into TV cliché-land; he might as well be wearing a Star Trek red suit."
- In his reference book Wanting to Believe: A Critical Guide to The X-Files, Millennium and The Lone Gunmen, writer Robert Shearman rated this episode 3 and a half out of 5 stars. "This is a decent old-fashioned monster story, given a new spin by being set in the new X-Files-less FBI," he critiqued. "What gives it an extra buzz is that it's Mulder, still in the throes of depression, who all but rejects the case – witness his disgust as he ventures down into the sewers on what he assumes is one more round of routine humiliation – and that it's Scully, still trying to find a way to give her former partner some purpose, who takes the steps to determine the unusual nature of his assignment. In addition, the mysterious phone calls telling Mulder that the successful outcome of the case is imperative for the reopening of the X-Files, and Skinner's own reluctant admission that lives would have been saved had the X-Files been active, give this deliberately familiar story of monster maraudings a greater sense of depth. There are some lovely ideas, too, about the way the FBI is ill-equipped to deal with prosecuting legal proceedings against a human fluke. It's comical to imagine a sea monster being brought to book in a courtroom, but it also helps illustrate that gulf between the show that was (in which Mulder and Scully get to pursue cases only limited by imagination) and the show that is (in which Mulder is still stuck on wiretap duty). It all peters out after half an hour's worth of action, and more's the pity [....] But this is largely a skilful horror story with some great (and grisly) set pieces [....] If by the end of the story you might feel this is just an ordinary X-File, then bring them on: as a baseline episode, this has enough flair and pace to satisfy."
- After the making of this episode, Darin Morgan and David Duchovny coincidentally sat next to each other on a plane bound for Vancouver, to prepare for "Humbug". As Duchovny was unaware Morgan had played the Flukeman, Morgan asked him to sign a book, addressing it to Duchovny's "nemesis." Though confused, Duchovny did so, after which Morgan revealed he had played the Flukeman. (The Complete X-Files: Behind the Series, the Myths and the Movies, p. 57; X-Files Confidential, p. 94) Duchovny was impressed Morgan had been willing to wait half an hour before pulling the prank. (X-Files Confidential, p. 94)
- The dire circumstances experienced by the crew while shooting at Iona Island Causeway served as a long-standing reminder. "For years afterward, no matter how ugly a location was, I'd remind Chris [Carter] of the sewage treatment plant," Al Campbell divulged, "pointing out that nothing could ever be as bad as that place. And we weren't going back there." (X Marks the Spot (On Location with The X-Files), p. 56)
- Although Chris Carter pointed out the Flukeman might return hereafter, Darin Morgan was insistent on not playing the character again. This was due to the discomfort he had experienced while wearing the Flukeman costume for this episode. (X-Files Confidential, p. 94)
Cast and Characters
- Darin Morgan, who played the Flukeman in this episode, is the brother of co-executive producer Glen Morgan and subsequently worked on The X-Files, his credits including the writing of episodes such as "Humbug", "Clyde Bruckman's Final Repose", "War of the Coprophages" and "José Chung's From Outer Space". He also wrote two episodes of Millennium – "José Chung's Doomsday Defense" and "Somehow, Satan Got Behind Me" – as well as directing both.
- During the making of this episode, David Duchovny never saw Darin Morgan outside of the Flukeman costume. They spoke to one another and got along. (X-Files Confidential, pp. 93-94)
- Gillian Anderson was heavily pregnant during the making of this installment. "The trick in this episode, as Gillian Anderson's pregnancy progressed, was to shoot her in ways to disguise her pregnancy," reported Chris Carter, "and there are lots of very fancy trick angles, well-placed trench-coats, and scenes where she is seated rather than standing, but I think now, when you look at her, when you go back to look at an episode like this, you see that she's got that radiant glow of pregnancy and that her face is fuller, and she looks so completely different now, it actually [...] [will] be a nice thing for her to, I think, go back and look at as her daughter grows up, to sort of remember what that was like." ("Chris Carter Talks About Season Two: The Host", TXF Season 2 DVD special features)
- Marc Bauer (Agent Brisentine) previously played Man in Suit in The X-Files episode "Ghost in the Machine".
- William MacDonald (Federal Marshal) previously played Dr. Oppenheim in The X-Files episode "Fallen Angel".
- Matthew Bennett as Craig
- Freddy Andreiuci as Detective Norman
- Don MacKay as Charlie
- Marc Bauer as Agent Brisentine
- Gabrielle Rose as Dr. Zenzola
- Ron Sauve as Ray
- Dmitri Boudrine as Russian Engineer
- Raoul Ganee as Dmitri
- William MacDonald as Federal Marshal