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

After exerting her powers beyond their limits, Blink goes into a state of shock, forcing Caitlin and Eclipse to go on a mission to find a special serum that will help her to recover. Meanwhile, Reed faces some difficult choices when it comes to helping his family, and Polaris runs into some trouble.

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 Inner Circle prepares for a secret ambush, but Polaris is reluctant to join and Reeva tasks Esme with getting Polaris on board. Esme confides in Polaris, revealing her and her sisters' troublesome past. Meanwhile, Thunderbird trains Reed on controlling his powers and The Purifiers attack The Mutant Underground as they attempt to rescue a group of homeless mutants.