In the aftermath of disaster, the Mutant X team must deal with the death of one of their teammates, the disappearance of another, the return of Mason Eckhart, and the arrival of a mysterious mutant with an agenda of her own.

The Mutant X team must stop a serial killer who leaves clues to his next victims in the form of puzzles.

When Lexa is unknowingly drugged with a lethal substance, the team must race to find the antidote before it's too late.

The Mutant X team is called in to investigate bizarre activities occurring at a local hospital.

Jesse is forced to reconnect with his former fiancé when the Mutant X team learns that her company is involved in the genetic manipulation of crops.

While Brennan and Shalimar investigate a mysterious plane crash, Lexa contemplates her future with the Mutant X team.

As the Mutant X team fights to retrieve a formula hidden in a collection of artwork, Shalimar is given vital information from a mysterious source

Brennan is forced to return to his criminal past when Mutant X discovers that his old partner is involved in stealing secrets from the Dominion.

Discovering that their teammate Lexa is the subject of a covert experiment that is controlling her, the Mutant X team hunts for the doctor responsible.

Brennan battles with a Guardian of the Prophecy to stop the late mutant Ashlocke's plan from beyond the grave of world domination.

Lexa's suspicions lead Mutant X to unveil a traveling death camp, which is posed as a circus for mutant refugees and Mutant X's enemy within the Dominion.