Ella sometimes gets mad at her brother, Leo. Mostly because he keeps ruining everything, like her science-fair project. But when Ella is kidnapped by aliens, it is up to Leo to rescue his sister and save the planet from an alien invasion. It's a lot to ask of a five-year-old. Fortunately, Leo has help. He has his trusty stuffed giraffe, also named Leo, and he has an overexcited spaceship, who is also named Leo. Together, these Leos will do their best to ruin an alien invasion, ruin a government conspiracy, and possibly also ruin a perfectly good pair of sneakers.