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.
The lives of an ordinary suburban family change course forever when they discover their children have developed mutant powers. When the threat of a hostile government forces the family to go on the run to protect themselves, they join the ranks of an underground network of mutants. Together, the group fight to survive in a world where fear and misunderstanding put them at constant risk.