Exploring the idea of The Mandela Effect, in which large groups of people remember an alternate history, Mulder and Scully find out how the X-Files themselves may really have originated.

In a world of ever-increasing automation and artificial intelligence, Mulder and Scully find themselves targets in a deadly game of cat-and-mouse.

When a pair of teenage girls attack one another, each believing the other to be a monster, Mulder and Scully find that their investigation could possibly lead back to their long-lost son, William.

Mulder and Scully investigate the brutal animal attack of a little boy in Connecticut, while suspecting darker forces are at play.

Skinner goes AWOL when his past comes back to haunt him. As Mulder and Scully try to track him down, their growing mistrust of him reaches its apex.

Mulder and Scully investigate a case where people are plagued by their own doppelgangers.

A chilling secret is revealed when an old friend reaches out to Mulder and Scully in a seemingly impossible way.

Mulder and Scully rush to find an on-the-run William while the Cigarette Smoking Man pushes forward with his ultimate plan.

Mulder and Scully learn that they aren't the only ones desperately searching for their long-lost son, William. The very fate of the world may depend on it.

While investigating human organ theft, Mulder and Scully uncover a mysterious cult consumed with macabre rituals.