Cyrus Vane, a soldier declared dead, wakes in a ruined Helix lab as the city of Halvern falls to an evolving plague. A system called ZERO PROTOCOL lets him absorb traits from the infected, but every mutation costs him a piece of himself. He fights through the outbreak looking for his younger sister Wren, who "died" in a Helix trial three years earlier, while Helix hunts him. He learns that the Protocol is not Helix's invention. It is the steering mechanism of an ancient organism that needs a human Keeper to control the infected. Six hosts have failed and become the world's deadliest monsters. Cyrus is Host 7, and Wren is Host 4. When Helix's CEO captures Wren to become the Keeper himself, the plague floods the world. Cyrus must choose between becoming the Keeper and losing his humanity, or burning out the system and losing the power that could save everyone.

Seven years ago, Damon Lockwood died on the floor of a church, trying to save a nine-year-old girl from a demon.Then the Devil offered him a deal.Now Damon is an occult fixer with a damned soul, a countdown branded on his wrist, and a talent for finding the loophole in any contract. Every time he borrows Hell's power, it costs him days of his life, burns another mark into his skin, and shows Hell exactly where he is. He has one goal: find a way out of his contract before the number hits zero.Then Lilith Vale walks back into his life.She was the Devil's lover. She knows Hell's laws better than anyone alive, and she's holding a copy of Damon's contract with a clause he never signed. She says she can help him escape. She's lying about something, and Damon can't tell what.Because Hell isn't hunting him for his soul. It's hunting him for what's inside it.A stolen power. An ancient name. And a Devil who can't afford to let anyone else find out what Damon is carrying.One damned man. One dangerous woman. One Devil who made a very expensive mistake.Hell owns his soul. But the contract never said who owns the Name.