With Ava and Beatrice lying low in Switzerland, a new cult grows in devotion to Adriel. Ava meets a young man who is part of a group opposing Adriel, and Sister Lilith hunts for Father Vincent.

After Adriel and his followers engineer a "miracle" to draw public attention, Adriel pays a visit to the Vatican. Mother Superion and Camilla meet a potential new ally, and Lilith seeks answers about her transformation.

Ava and Beatrice are reunited with their sisters in Madrid, where the newcomer Yasmine claims to be able to lead them to an object that can defeat Adriel. Lilith crosses Dr. Salvius's portal to another realm, and Pope Duretti deals with the enemy's influence in his midst.

The Order is forced to regroup after Ava is captured by the enemy, and desperate Lilith turns to Adriel for answers about what she is becoming. Ava learns that there is more to her new friend Miguel that she believed.

Ava and her sisters set out in search of Lilith, who is falling under the enemy's thrall. The Pope summons Mother Superion to a secret conclave to determine a course of action, and Dr. Salvius is reunited with her son.

While Adriel and his followers prepare for a major media event, the Order prepares to move against him and his followers. Michael reveals to Ava what he has been sent back to do, and Lilith chooses a side.

With Adriel's power in ascendance the members of the Order despair over their failure. While Camilla is held prisoner by the enemy, Ava finds an unlikely ally.

Ava returns from a visit to the other realm with a plan to stop Adriel, though she knows that her mission will come at great personal cost – both to her and Michael.