The Thundermans are visited by High Tide, the former protector of Secret Shores. But when they explain to him that they are the new superheroes in town, he decides to take back his old role, even if it puts Jinx and Booch in danger.

Max seeks help dealing with a mystery prankster at school from his old principal, who was always the target of his pranks. But Max fails to stop the pranks and quits the mission, prompting Chloe to confess that she was the prankster all along.

Chloe is struggling with her leadership skills, but when a villain attacks her school field trip, Max and Phoebe have to put Chloe in charge while they try to take down the villain and defuse his dangerous astronomical weapon.

Chloe must attend summer school, and Max is assigned to be her teacher. While they will be busy all summer, Phoebe decides to go solo on missions. She meets a new superhero named Captain Perfect, and discovers they make a good crime-fighting team.

Max learns that Phoebe is working with Captain Perfect, and sets out to uncover the secret he is keeping. Chloe's crush invites her to a product launch party at Splat By The Sea, at the same time Jinx and Booch want her to protest outside the party.

Upset that Phoebe has a new partner, Max decides to partner with his friend Gideon. But things backfire when Max tries to turn Gideon into a supersized superhero. Chloe's friends pretend to be wealthy so they can bond with her new crush.