Watch out, all you mythological beasties roaming the streets of San Francisco - There's a new kick-ass team of demon-fighters coming your way - Meet Grace, who just moved to San Francisco. It's a tiny bit scary, starting over, but it gets scarier when a minotaur walks in the door. And even more shocking when a girl who looks exactly like her turns up to fight the monster. Then, there's Gretchen, who is fed up of monsters pulling her out into the small hours, especially on a school night. Getting rid of a minotaur is just another notch on Gretchen's combat belt, but she never expected to run into this girl who could be her double in the process. And Greer, who has her life pretty well put together, thank you very much. But everything tilts sideways when two girls who look eerily like her appear on her doorstep and claim they're all sisters. These three teenage descendants of Medusa must reunite and embrace their fates in this unique paranormal world where monsters lurk in plain sight.