Meticulous attorney Margaret Wright hires her scruffy son as her law firm's in-house investigator.
When a serial killer "Over There" starts piling up victims, the Fringe Division gets involved with the investigation.
A spate of deaths, in which the victims were plagued by their own doppelgangers, lead Mulder and Scully to a pair of twins playing a dangerous game.
When Lassiter loses his nerve, he gets Shawn and Gus to help him take down a dangerous criminal.
Darius reveals his secret to Rachel; Rachel tries to find a way to reverse Darius' decision; Quinn and Chet find themselves back on the same team; Chet brings his baby to work; Quinn confronts Rachel.