A teenage boy with a mysterious past. A lost prophecy. An ancient relic of divine power. A hidden war between Earth and Hell.

Fourteen-year-old Zak Fisher has always known he’s different. He’s an orphan, he’s never been ill, and he’s stronger and faster than anyone else his age.

When he's attacked by Nightwraiths, he’s rescued by a Templar Knight and discovers the truth: Hell exists in a parallel world, and he's destined to play a vital role in an ancient war between the Templars and the Hell King, Morloch.

Taken to Avernon Monastery in Cornwall, Zak meets Dunk, Leah, and Sarah – three teenagers who are also orphans, share his birthday, and his extraordinary abilities. Together, they learn they’re Angels, and will gain their full powers on their fifteenth birthday.

However, the evil Lord Ballivan is searching for the Seal of Solomon, a legendary ring capable of opening a portal between Earth and Hell. If he acquires it, Morloch’s forces will be unstoppable – that's unless Zak and the other Angels can find it first.