Seventeen-year-old Esme Pearl has a babysitters club. She knows it's kinda lame, but what else is she supposed to do? Get a job? Gross. Besides, Esme likes babysitting, and she's good at it.

And lately Esme needs all the cash she can get, because it seems like destruction follows her wherever she goes. Let's just say she owes some people a new tree.

Enter Cassandra Heaven. She's Instagram-model hot, dresses like she found her clothes in a dumpster, and has a rebellious streak as gnarly as the cafeteria cooking. So why is Cassandra willing to do anything, even take on a potty-training two-year-old, to join Esme's babysitters club?

The answer lies in a mysterious note Cassandra's mother left her: "Find the babysitters. Love, Mom."

Turns out, Esme and Cassandra have more in common than they think, and they're about to discover what being a babysitter really means: a heroic lineage of superpowers, magic rituals, and saving the innocent from seriously terrifying evil. And all before the parents get home.