After the Vampire Magician's attempt to free Lucifer in Chicago, the Ancients are on their way to Thermopolis, Wyoming, to hold the Vampire Sheriff accountable.

During the battle of Chicago, the demon Legion escaped from Hell and is determined to open Hell's Gates.

Sam Harlan and Callie Calahane will have to call upon every friend and ally if they want to get out of Thermopolis alive.