Reeva prepares to carry out her plan for the Inner Circle, but not everyone is on the same page. Reed struggles to manage his powers and the family realizes that without enough of the serum, it's only a matter of time before he completely loses control. Frustrated and egged on by Benedict Ryan, Jace and the Purifiers are on the attack, but for Jace, things aren't as black and white as they once were.

At a moral crossroads, Jace is forced to hand over something valuable to Dr. Campbell. The team at Mutant HQ is divided on what they should do next, so Reed and Caitlin take matters into their own hands.

Polaris learns more about her past and makes a crucial decision that could have impactful consequences. Meanwhile, the Mutant HQ comes under attack and, with everything to lose, relationships are put to the test and alliances shift.

The group faces a threat when they discover a new refugee is a spy working for Sentinel Services; Reed visits his estranged father and learns secrets that could prove useful.

Dr. Campbell attends an anti-mutant summit, attempting to take the Hound program national, and some of the team at Mutant HQ goes on a dangerous mission to stop his efforts.

A suburban couple is forced to flee from a hostile government after their teenage children begin to show they possess certain powers.

When the mutants devise a plan to take down Sentinel Services, Eclipse seeks out an old friend from his dark past in order to obtain some useful information. Meanwhile, Lauren and Andy attempt to combine their powers in order to help the group.

Lauren can't access her powers when it matters most, leaving Caitlin to take matters into her own hands when they are being pursued. Reeva finally reveals her plan for the Inner Circle and it's darker than anyone could have imagined. Meanwhile, Jace confronts some regrets about his actions and is torn between pressures from the Purifiers and his own beliefs.

The team develops a risky plan to help mutants who are in Sentinel Services' custody. Reed reveals details to Andy and Lauren about the Struckers' family history that could prove to be a game-changer.

As Caitlin and Thunderbird struggle to save the life of a mutant injured in the Inner Circle's chaotic liberation of a psychiatric hospital, they discover clues to the identity of the powerful mutant Polaris and Andy were sent to retrieve. Meanwhile, as Jace joins up with the Purifiers to chase down the escaped mutants, he comes dangerously close to colliding once again with the Mutant Underground.

Polaris' baby begins to suffer from a deadly illness, leaving the Inner Circle unable to heal her, and prompting them to turn to an unexpected source for help. Meanwhile, Reed and Lauren take an excursion to deliver illegal meds, but Reed's powers complicate their plans. Then, Thunderbird and Blink meet the leader of the Morlocks - a shadowy group of mutants that live underground - who offers to help them find the Inner Circle, but the two factions may not have the same goals.

Thunderbird contacts a mutant lawyer who recruited him to the Underground years ago, hoping she can help him find the Inner Circle. Lauren and Andy have a shared dream, which distracts Andy from his training and prompts Reeva to consider cutting her losses with him, which, in turn, makes Andy second-guess his separation from his sister. Meanwhile, Reed must keep a huge secret from the group and Jace picks up the mutants' trail again

The Struckers, minus Andy, begin to rebuild their broken trust, while Thunderbird, Blink and Eclipse visit Wire, hoping to convince him to help again. But when they get there, they learn that something terrible has happened from Wire's brother, Graph. The team discovers that the Inner Circle is on the way to raid a mutant detention facility, so they make moves to try to intercept them. Meanwhile, Jace is contacted by a member of the Purifiers.

In attempts to stabilize Reed's powers, Reed, Caitlin and Lauren meet with Dr. Risman, a doctor who treats patients with debilitating X genes. However, Lauren finds out Dr. Risman is not who she thought she was. Following the Inner Circle's bank ambush, Thunderbird and Blink continue to work together to chase them down. Meanwhile, Polaris reflects on her troubled relationship with her father and takes steps to protect Dawn from the Inner Circle.

Reed worries as Lauren becomes intrigued by her ancestors and their violent powers. Lorna begins to reevaluate her trust in the Inner Circle after figuring out the past of Reeva's new trainees. Meanwhile, Benedict Ryan continues to encourage Jace to take action with the Purifiers. Marcos asks Clarice to go to the Morlocks in search of information on the Inner Circle and Thunderbird gets a call from Evangeline.

With the Inner Circle and the Purifiers on the rise, and the nation more divided than ever, the dream of the X-Men is on the verge of failure. In attempts to revive the Mutant Underground, Evangeline proposes a country-wide meeting. Meanwhile, Lauren and Andy continue to disagree in their dreams and the Frost Sisters attempt to intervene. Caitlin makes the risky suggestion of connecting with a family member for vital intel, and Lorna tries to secretly investigate Reeva's plans for the Inner Circle.

Reeva Payge purges the Inner Circle of those who disagree with her, leaving her completely in charge. Then, fast-forward six months, when the Mutant Underground saves a girl, but not her family, from a Sentinel raid. Against the group's wishes, Eclipse and Caitlin meet with a criminal hacker to get info on the Inner Circle. Meanwhile, Polaris prepares for the birth of her baby, her contractions magnetizing anything metal and wreaking havoc. She also makes Andy promise to save the baby, no matter what.

Eclipse's ex-lover returns; Reed and Sage find alarming information about Lauren's new friend; Thunderbird helps Blink open up about her past; Jace approves a special surveillance program.