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 the auction of a highly lethal substance that a number of notorious international terrorists are vying to acquire.

The Mutant X team is brought in to help a military base that has become infected with a deadly disease.

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.

The Mutant X team embarks on a mission to locate and capture a powerful super-mutant who possesses god-like powers.

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.

A revenge-seeking cybernetic mutant uses his powers to overtake Sanctuary's security system in a plot to destroy Mutant X.

The Mutant X team learns about Lexa's estranged twin brother when he becomes the main target of an underground operation harvesting mutant organs.

Brennan and the Mutant X team join forces with a time traveling mutant to diffuse a bomb threatening devastating consequences.

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

Mutant X tracks down a rogue scientist while Shalimar breaks away from the team to help Adam save the scientist and uncover the real bad guy.

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.

Mutant X unearths an old military experiment involving an age-reversal serum and is surprised to discover that Jesse's grandfather is a one of the test subjects.

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.

When Jesse's life hangs in the balance, Brennan must connect to him and lead him through past memories they've shared in order to save his life.

Mutant X must stop a scientist from cloning women for use as slaves in his ultra-exclusive men's club.

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

The team uncovers many of the mysteries surrounding Mutant X after the Dominion captures Lexa and Jesse.