Gabby Duran constantly feels like she's living in the shadows of her polished, successful mother and whip-smart younger sister. She finally finds her moment to shine when she inadvertently lands an out-of-this-world job to babysit an unruly group of very important extraterrestrial children who are hiding out on Earth with their families, disguised as everyday kids. Fearless and bold, Gabby steps up to the challenge to protect these youngsters and their secret identities, and prove she's the best babysitter in the galaxy.