The episode begins with a stakeout at a bank. Criminal Warren Dupre has broken in but Scully's old boyfriend and FBI-agent is shot. Scully then manages to shoot Dupre. Everything seems just fine when doctors are able to bring Willis back from the dead but later Mulder is not so sure which person came back on that day when Willis begins acting strangely.

After escaping from the hospital, Willis goes in search for Dupre's lover and partner in crime, Lula although she has no idea that Willis' body has been inhabited by the dead criminal. When Lula is not there, Willis goes in search for her brother as he believes that he was the one that tipped the FBI off about the burglary. Willis kills him and then shows up at the crime scene while the investigation into Lula's brother is going on. Little do they know that the murderer is standing right next to them.

Mulder, still not convinced that Willis is REALLY Willis, decides to test him as he has learnt that him and Scully have the same birth date. Although Scully's birthday is months off, Mulder gives Willis a birthday card for him to sign for Scully and he does it with his left hand even though his records show him to be right-handed. The evidence is right there for Scully but she is still skeptical and decides to go with Willis instead as he says he had located Lula.

When they find her, Willis puts a gun to Scully's head and handcuffs her while telling Lula that he will prove that he is really Dupre. They hold Scully hostage while Lula rings the FBI demanding a $1 million ransom in return for her safety. While on the phone to her, Mulder hears an unknown background noise and when anaylsed it is found to be the sound of an aeroplane. He is able to track down Scully.

But meanwhile, Willis is dying as Scully tells him that he is a diabetic. Lula will not help him as she reveals that she was the one that tipped off the FBI as she wanted the money for herself. Faking death, Willis suddenly takes the gun off Lula and her kills her just before he dies himself. The FBI run in and Mulder runs to Scully comforting her. She has been saved!

Back in Washington, Scully is rifling through Willis's stuff and finds that his watch stopped at the exact same time as he went into cardiac arrest. Mulder tells Scully who doesn't understand what it means, "It means whatever you want it to mean".