Mulder and Scully are perplexed by two murders committed at the exact same time, but on different coasts.
Mulder negotiates a hostage situation with a former FBI agent who claims to be the victim of an alien experiment.
Not knowing whom they can trust, a reunited Mulder and Scully must continue their investigation without the help of the FBI.
Beka's uncle Sid, who once tried to murder her, turns up and announces his intention to stand for leader of the Commonwealth, but is Beka the only one holding a grudge against him?
When the team find themselves in the middle of an alien invasion, they soon discover that the invaders have slider technology as well.