Dr. Secare was an old friend of Dr. Terrance Allen Berube. When Berube started an experimental program in which six terminally ill patients were treated with extraterrestrial gene therapy, Secare – dying of melanoma cancer – entered into the program. In common with the five other patients, Secare began to recover from his illness, as a result of the gene therapy. However, he also developed inhuman strength and the ability to breath underwater. He now had an alien blood chemistry and his blood was toxic to humans. Secare nonetheless spent a while, thereafter, living a reasonably normal life. Secare's survival was never intended by others attached to the test program aside from Dr. Berube, since they deemed the possibility of having a hybrid living out in the real world as too great a risk. Secare warned Berube of this situation.
On Sunday, May 8 1994, Dr. Secare fled from police officers. He led the officers, driving Dr. Berube's silver Sierra, on a high-speed car chase over a distance of more than sixty miles. His fleeing was motivated by fear he would be killed by the same people who meant to cover up the truth of his hybridized physiology, although the police were under the impression the chase was because Secare wouldn't pull his car over for a moving violation. Secare was pursued by the police to Ardis harbor, where Secare left the Sierra, on foot. He tried to clamber over a nearby fence but was assaulted by two policemen armed with billy clubs. Since their blows didn't subdue him, Secare retaliated against the officers, snatching one of the clubs and using it against the two policemen. Not even a taser was sufficient to down the fugitive. Secare ran up a flight of dock-side stairs while the same officer who had tried to taser Secare shot him twice. Secare dived into the water below, leaving a trail of green blood on the uppermost step.
Dr. Secare, during an intense manhunt for him, hid in the water for three days, after which the search was called off. However, Secare was meanwhile being hunted by an assassin, the "Crew Cut Man", who killed Dr. Berube. After emerging from the water, Secare called Berube's home office. Though FBI Special Agent Fox Mulder – who was investigating Secare and the hybridization experiments he had been involved in – answered the call, Secare was under the mistaken impression he was talking with Berube. Secare doubled over with pain, midway through the call, which was secretly listened into by the Crew Cut Man. Secare was later rushed away by an ambulance. When the paramedics tried to operate on him, toxic gas from Secare's blood poisoned the paramedics, making them cough and their eyes sting.
At around the same time as Mulder began trying to find Secare before he could be located by those who wished to kill him, Secare went to Berube's house. He hid in the attic at the top of the building. When Mulder arrived there, Secare tackled him but the struggle ended with Mulder pledging to protect Secare. Moments later, Secare was shot in the back by the Crew Cut Man, indirectly affecting Mulder with the the noxious gas from Secare's blood. His corpse was taken out of the attic in a body bag, transported by two associates of the Crew Cut Man, both of whom wore gas masks. (TXF: "The Erlenmeyer Flask")
In the final draft script of "The Erlenmeyer Flask", Dr. Secare is described as "mid 40s, bearded" and white-skinned.
Dr. Secare was played by actor Simon Webb. Though the character leads a manhunt underwater in "The Erlenmeyer Flask", Webb was actually terrified of water. The production staffers of The X-Files were unaware of this when he was cast in the part, learning about his fear only later. ("The Erlenmeyer Flask" audio commentary, The X-Files Mythology, Volume 1 - Abduction special features)