Set in the Dark Ages of the DC Universe, a barbarian horde is massing to crush civilization. It's fallen to Madame Xanadu and Jason Blood, the man with a monster inside him, to stand in their way – though the demon Etrigan has no interest in protecting anyone or anything other than himself! It'll take more than their own power to stop an army fueled by bloodlust and dark sorcery, and some very surprising heroes – and villains – will have no choice but to join the fray!

Four centuries ago, the last night of Camelot. King Arthur's body is being taken away for safe keeping, and Excalibur is given back to the Lady of the Lake. Meanwhile inside the burning castle, Merlin puts the Demon Etrigan into Jason from Norwich, permanently connecting the two.

Later in the Dark Ages, The Questing Queen and her army are marching across the country taking anything they want from the people of the land. Jason, Xanadu and Vandal Savage are at a tavern when the army arrives and Jason transforms into Etrigan. This calls the attention of the Questing Queen who sends dragons to destroy the city.