The year is 64 A.D. -- though now A.D. stands for Anno Daemonii. Demons have crossed a gate into our world, taking the reins of power from humanity. A new Inquisition has begun, determined to root out any who stand against the new world order. The holy sites on earth have been destroyed -- Jerasulem first, then the Vatican, then Mecca -- and what resistance remains is ruthlessly crushed. Amaranth is a fighter in the resistance cell based in London. Dham is a Ringer, one of the few people left able to ring the remaining sets of blessed hand bells that have power over demons. When Amaranth discovers that her best friend has been possessed by a demon and is going to be used in the Resistance's final, desperate mission, she asks Dham for his help in saving her friend. With the Inquisition closing in and betrayal threatening from inside the Resistance itself, Amaranth, Dham, and the demon -- along with Catriona, a new, highly-skilled, highly-blonde bell-ringer -- decide to head to Rome and the ruins of Vatican City, hoping to find a way to stem the tide of demonic possessions and close the gate.