Geneva, 1630
Simon Kent races across the rain-battered landscape, haunted by a thousand regrets. He has only one mission now: deliver the book. He must succeed. Too many have died already for him to fail.

London, 1816
The moment that Mary Wollstonecraft locks eyes with debonair poet, Percy Shelley, she knows her life will never be the same again. Illicit love letters, stolen moments and tantalising touches make up their whirlwind romance, but when outside forces threaten to break them apart, there seems to be only one option left to them: run away to Italy. But thunderous skies await them there.

When Mary discovers an ancient book of spells that’s been hidden for centuries, she is suddenly thrust into a world that is larger than ever seemed possible. But the book was hidden for a reason, and she soon realises that they’ve awoken something else. Something from the very depths of hell, and it's hungry for blood.

Mary must destroy the creature before it's too late. But no one can be trusted, and people aren't always what they seem.