Phoebe and Max are assigned a mission in their new hi-tech beach home base, where their superhero identities remain a secret. They bring Chloe along to help her have a normal life, but the trio must stop the threats of Secret Shores and the true supervillain known as the Mastermind.
A training accident makes Chloe's powers faulty. Max tries to cure her and gets a misleading positive result, so she goes to a party. But his treatment actually creates brand new powers Chloe can't control, so the twins have to get her out!
Chloe, Jinx, and Booch are designing a school mascot, but Max and Phoebe's feud over their jobs ruins the project. Chloe reads them the riot act, and the twins realize their twin-fighting affects Chloe now that they're guardians.
After Phoebe and Max let Chloe's friends watch a horror movie and eat candy, Jinx and Booch's parents want to meet Chloe's. With Hank and Barb away, Max and Phoebe transform into them to help Chloe. It goes well until the real Hank and Barb show up.
Max bets Phoebe she can't turn off being a superhero and go on a normal date. Chloe helps Phoebe do well on the date, but Max tries to sabotage by crying wolf. Suddenly, a real supervillain emerges and puts Max and Chloe in serious danger.
Cherry visits and Max discovers Phoebe never took her sparkle power away. Phoebe promises to do so and has a girls' night with Cherry while Max hosts Jinx. Colosso gets jealous, and Cherry's powers malfunction, nearly blowing Phoebe's cover.
A new super-fast villain is wreaking havoc in Secret Shores, and Billy is the only hope at tracking her down. After Billy's speed accidentally triggers an avalanche, however, he decides to hang up his cape and retire from being a superhero.
Max and Phoebe attend Parent-Teacher Night, leaving Chloe to have friends over without adult supervision. Jinx finds the Air Lair and believes spies are targeting the school, and his meddling puts Max and Phoebe's school jobs at risk.
Chloe feels smothered by Max and Phoebe, and encourages them to make new friends. However, the twins unwittingly make the same friend, and begin a battle for the ages over her. Chloe's new alone time is interrupted by living room-crashing pelican.
Billy arrives, hopeful that his new sidekick Steve can join the T-Force. Phoebe and Max consider it, but soon discover that his superpower is making marshmallows. After they reject Steve's bid to join the team, he turns evil and vows revenge.
The former protector of Secret Shores arrives at the Thundermans' beach house and reclaims it as his home. Phoebe, Max, and Chloe try to reason with him, but when a protest at the school goes wrong, the former hero proves more harmful than helpful.
After Max is targeted by a mystery prankster at school, he seeks help from Principal Bradford. But Max fails to stop the pranks and quits the mission in embarrassment, prompting Chloe to confess that she was the prankster all along.
Chloe doesn't want to learn leadership skills. But when a villain attacks her field trip trying to steal a space geode, Max and Phoebe have to put Chloe in charge while they try to take down the villain and defuse his dangerous astronomical weapon.
Chloe has been missing school by going on missions with her siblings. She now has to go to summer school to catch up on everything she has missed. Max, acting as the substitute for summer school, has a new student who agrees to tutor her.
B.C. invites Chloe to a launch party, and at the same time Jinx and Booch invite Chloe to protest outside the party. Not wanting to hurt anyone's feelings Chloe tries to do both. Phoebe is keeping her working with Captain Perfect a secret from Max.
Upset that Phoebe secretly partnered with Captain Perfect, Max decides to have a new superhero partner, his best friend Gideon. But things go wrong when Max tries to make Gideon a better superhero.
Captain Perfect's younger sister, Penny, is headed down the path of becoming a supervillain. Eager to impress Captain Perfect, Max takes it upon himself to guide her toward a better path.
Max flees from Phoebe and Captain Perfect to prove his innocence when he is wrongly accused of committing a crime.
Max pretends to turn evil to infiltrate Mastermind's henchmen and steal the Chip-Chucker, a device that previously turned him evil.
Max misses being famous and having fans, so he decides to break Booch's sandwich-stacking record to be famous again. Chloe rallies behind Bootch so that she can take back her record.
Mrs. Wong visits Secret Shores, and threatens to reveal the Thundermans' superhero identities to the town. But Max and Phoebe's plan to have Dr. Colosso keep her quiet backfires in ways they could not have imagined.
With Cherry working at Splat by Sea, Max ropes her into a fake dating scheme to score discounts at the restaurant. Chloe faces a tough choice between winning a trivia competition or supporting her brother Billy when he wants to join her team.
Chloe's birthday party is cancelled, and Max and Phoebe compete to throw her a new one. When Max's time-stopping birthday gift falls into the wrong hands, he must work with Phoebe to stop some party poopers from ruining Chloe's birthday.
Max and Phoebe discover that Lazlo Chance may be the evil Mastermind and enlist Chloe to help. But when Chloe is torn between her head and her heart, it threatens the entire mission.
