September 1943. The world is at war. Leo Avery has been left with nothing. His home is gone, destroyed in the Blitz, and his only family - his father - has mysteriously vanished.

When Leo is attacked by a terrifying creature, he is saved from death by a group of strangers calling themselves Angels. Led by the enigmatic Dr Heller, this rag-tag band of hunters wield strange, arcane powers, using them in the fight against monsters they know as 'dreadfoul'.

Leo is soon thrust into a war against the very worst man and myth have to offer, battling both the dreadfoul and the men who intend to use them to create an unstoppable army.

With the threat of Armageddon looming ever closer, Leo quickly finds himself torn between his new destiny and the search for his missing father - only to find the two are more closely linked than he could ever have possibly imagined.