Seven Deadly Sins (Allison Brennan) Books in Order

This is Allison Brennan stepping away from straight crime fiction and into supernatural suspense, but she does not leave the danger behind. The Seven Deadly Sins books are built around Moira O'Donnell, a demon hunter with a brutal family history and powers she never asked for. Her mother, Fiona, is a black witch with frightening reach, and that mother-daughter conflict gives the whole series its spine.

Moira is not a cozy paranormal heroine. She is angry, capable, scarred, and always a little too close to the darkness she is fighting. That tension matters. She hunts evil, but she is also tied to it by blood, which means every victory costs her something. Brennan gets a lot of mileage out of that push and pull.

The books start with Original Sin, where Moira tracks Fiona to a California town on the edge of catastrophe. From there the series widens into a bigger war involving demons tied to the deadly sins, old magic, and a secretive religious order trying to contain the damage. In Carnal Sin, the fight moves to Los Angeles as another demonic force takes hold. By the later stories, including Ghostly Justice and Mortal Sin, the stakes turn even more personal.

Rafe Cooper is the other key piece. He is not there just to provide romance, though the chemistry between him and Moira is part of the appeal. He is a damaged believer with his own history, and together they make the series feel more grounded than the premise might suggest. Brennan keeps pulling the story back to trust, guilt, loyalty, and what it means to fight evil when you do not feel entirely clean yourself.

The tone is dark, fast, and often pretty grim. These are not books about charming magical communities or playful occult adventures. They are about possession, ritual violence, corrupted faith, and people trying to stop hell from leaking into the everyday world. Even so, Brennan still writes with a thriller engine, so the books move quickly and the cases never sit still for long.

If you are coming to this series from Brennan's FBI and private investigator novels, expect a sharper supernatural edge but the same interest in survivors, family wounds, and hard choices. Start with Original Sin and keep going in order. This is one of those series where the mythology, the relationships, and the emotional damage all build on each other.