Peanuts (or as he named himself: Simon White-Thatch Potentloins) was a super intelligent chimpanzee that contacted the Lone Gunmen to be rescued from the laboratory he was kept.
He sent the Lone Gunmen an e-mail and an audio recording via the account of Dr. Hasslip. The Lone Gunmen assumed it was a prank being played on them but when they went to the Boulle Behavioral Laboratory, Jimmy Bond pointed out Peanuts waiting for them at the chain link fence's gate just like the message had said. Jimmy Bond went and cut the padlock only to be pounced on by the freed Peanuts. He hid in the van of the Lone Gunmen as they escaped with Yves Adele Harlow.
The Lone Gunmen tried to talk with Peanuts after they retrieved him but they were still unconvinced he was super intelligent. When Peanuts is messing with their gear, Melvin Frohike sets him aside only to find Peanuts stole the keys to the van. He ran outside and climbed into the van but found Yves Adele Harlow waiting for him. At this point, the Lone Gunmen and Yves brought him back inside and it all became clear. Harlow had been more willing to believe he was a super intelligent ape because she had heard of the Boulle program for years: a program to create super intelligent animals to act as spies or assassins. They give Peanuts a laptop, finally realizing he doesn't have human vocal cords, and Peanuts tells them that his name is Simon White-Thatch Potentloins through the voice program he downloaded. Simon uses Edward Woodward's voice to speak to them and he explains that he doesn't trust them as they didn't seem much better than his previous captors. Simon does not wish to cooperate with them since humans don't care about animals so why should he be interested in human politics.
Simon gives them a story about another super intelligent chimp, Bobo, who will assassinate a French minister of trade at the DC zoo. John Fitzgerald Byers, Frohike, and Harlow leave to stop this, leaving Richard Langly alone with Simon. The others ask Simon to help Langly hack the lab's computer systems. Langly starts to make a tire swing for Simon while Simon sends the facility a fake ransom demand to bring the military there. Simon hides in a package and is picked up moments before the MPs arrive and arrest Langly, who has been tied up upside down by the chimpanzee.At the zoo, Yves Adele Harlow captures a chimpanzee she believes is Bobo but is actually Simon/Peanuts. When her and Frohike attempt to trade this chimp that they try to pass off as Simon without realizing it is Simon, Dr. Hasslip rubs paint off the ape's head, believing it to be some other chimp. Jimmy Bond figures out it is Simon/Peanuts and that the way to save him is to pretend to give up where Peanuts is. With Hasslip and the MPs leaving with Bobo, Jimmy Bond gives a laptop to Simon and lets the chimpanzee explain the reason for his manipulation of them all. Apparently, Simon/Peanuts wanted to escape but also to be with Lady Bonkers, who had been removed from the lab by Dr. Hasslip. Simon/Peanuts thanks them, points out how they should have more respect for Jimmy Bond who was the only one who paid attention to the chimpanzees looking any different from each other, and relates that he will stay at the zoo even though it is a cage because "the whole world is a cage when you're trapped in it alone."