Every fangirl's daydream is about to become Milly's nightmare.

When Milly arrives home to discover that her mum has been taken over by something very evil, she finds herself in mortal danger. But the last people she expects to rescue her are the boys in the hottest band on the planet!

Enter SLAY - playing killer gigs, and slaying killer demons. Suddenly Milly's on the road with JD, Tom, Niv, Zek and Connor, helping save the world, one gig at a time...