An alien security officer comes to Earth to track fugitives from his planetary system who have taken over the bodies of Earthmen. Unfortunately, while they enter human bodies and thus have a knowledge of humanity, the alien bases his physique on a poster of an underwear model for the Cole brand. Thus the alien (""Cole"") is pretty much clueless about humans and human physiology. A passing bar owner, Mel Porter, takes pity on him and takes him back to her hotel. ""Cole"" quickly cobbles together some Earth technology to track one of the escapees, Rhee, who killed his wife and child. He defeats Rhee thanks to his ""time-stop"" abilities and removes her essence from the human body she inhabits. He also meets Zin, a scientific genius and alien who masterminded the escape. At the end Mel takes on Cole full-time at her bar while Cole prepares to track more of the escapees.

Using his extrasensory powers, Cole figures out how Zin got his confederates into Chicago: by taking over the passengers on a train. Although Cole taps into the station's camera, he can't get a clear look at who they are. Meanwhile, an Inixian named Kaden is distributing an alien drug not only to his fellow criminals, but to humans as well. One of Jess' friends has a heart attack induced by the drug. Cole tracks the gas emissions caused by the drug production and follows Kaden to one of his traveling drug-clubs. Displaying a new ability to temporarily change his body, Cole duplicates one of the guards and manages to get close enough to Kaden to capture his life force.

Cole is in the middle of pursuing Trof (an Enixian) and about to lose his life when a concealed alien, Nestov, comes to his aid. Cole captures Trof and then prepares to capture Nestov, who asks for his help. Nestov's host, Darian Fawley, was on the train returning with money from a kidnapping when Nestov and the others took over the people on the train. Now Nestov has the money but the rest of the kidnappers are after him because he gave the money to Zin. Cole agrees to help. The kidnapping is still underway, with the kidnappers holding the girl ransom for yet more money. Cole and Nestov track down the girl, only to discover that she had created the whole scheme along with Nestov's host body to get money from her rich father. Cole captures the girl and her accomplice, but lets Nestov go in appreciation of his help...and as a future resource in his attempts to capture the other prisoners.

A blind man is led into the middle of an intersection and left to be run over by his German Shephard. While picking up Mel from an aborted date, Cole senses the presence of one of his prisoners, and soon determines the German Shephard has been taken over by one of the last arrivals on the train: Medoran, Zin's bodyguard. Zin is putting his bodyguard to use, killing a councilwoman who stands in the way of his desire to have a district of Chicago rezoned. Cole tracks down the dog, which can shift forms into a werewolf-like humanoid, and manages to capture it.

Mel is talking with Det. Bruno, and how he's being taken off the investigation into the mysterious disappearance of her boyfriend, restaurant owner Rod Archer. Cole overhears the conversation and takes on the form of Archer. Mel is understandably upset, but then realizes what Cole has done. Cole can't reverse the transformation, and decides to investigate Rod's disappearance. Several folks working for gangster Marco Sylvestri start gunning for ""Rod"", and then Rod/Cole gets grabbed by the Feds and dropped off at a home 50 miles outside Chicago, and informed he is a member of the wintess protection program. Rod and the Feds faked his death so he could testify against Sylvestri. Rod has started up a new life, which includes a wife and newborn child. One of the Feds is a mole, and tells Sylvestri of Rod's location. Cole and Mel anonymously get Rod and his family out of the house. Cole-as-Rod takes his place, and fakes being killed by Sylvestri. while grabbing a piece of evidence and sendin

Zin hires the billboard actor whom Cole based his physical appearance on to participate in his plan to frame Cole for murder.