"When her teacher assigns a new team project for Earth Day, Ellie can't wait to pair up with her best friend, Hannah. After all, as a superhero, it's Ellie's job to save stuff--including the planet! But the project soon becomes more than Ellie's super-skills can handle. She decides to use one of her parents' super inventions to create a copy of herself. But when Ellie #2 threatens to take over, it's up to the real Ellie to bring the project back down...

Superhero Ellie Ultra is given the responsibility of caring for Squeak, the class hamster, for the weekend, which is exciting, but also a little worrying, especially since her dog, Super Fluffy, is too interested in the hamster for comfort--but when she accidentally shrinks herself down to three inches tall Ellie discovers that, even for a superhero, pet sitting is a lot harder when you are no bigger than your pet.

Although she has battled supervillains, Ellie has recently become scared of the dark, so when she is invited to a Halloween sleepover at her best friend's house she is apprehensive--but when the villainous Fairy Frightmare sprinkles the girls with bad dream dust, trapping them all inside their nightmares, Ellie must squash her own fears to rescue her friends.

Ellie is looking forword to making new friends at Camp Hero, but her cabinmates, the Winter twins, whose power is to freeze things, do not seems to want to play with her, so Ellie uses her parents' latest invention to make them friendly--but it backfires when the twins start fighting each other over who Ellie likes best, and Ellie realizes that forcing someone to like you is not really cool.