In the beginning was an angel, a church and a knife.

For two thousand years the immortal known as Cross has wandered the world as a drunkard, a soldier, a thief and a hunter of angels. When he is lured to Barcelona by a particularly mysterious angel, he finds himself caught in the middle of a holy war among the Fallen. If he can manage to survive it, he may win the only prize he truly desires: revenge on Judas, a forgotten god of a forgotten people who has destroyed everything Cross ever loved. The only catch is he must first find the real Mona Lisa, the inspiration for da Vinci's painting. Like Cross and Judas, Mona Lisa is not what she seems to be.

As Cross's quest takes him around the world and into the secrets of his own past, he must look for help in the strangest places and from the most fantastical of characters, including gorgons, the faerie and Alice from Alice's Adventures in Wonderland. For everything hangs in the balance. Even the fate of the world.