When B.C. forces Chloe to steal a magical amulet that grants him superhero powers, the Thundermans unite to stop his plan; Chloe must reveal her identity to save her friends.

When Chloe's dangerous new power emerges, she's ordered to superhero boarding school. The family divides as Phoebe, Barb and Billy hide with her, while Max, Hank and Nora pursue them, leading to a battle over their future.