PE-ORDER: ON SALE DATE: October 4, 2025

Seductive magic. Deadly betrayal.

Don’t miss the explosive finale of the dark, romantic fantasy of the New York Times-bestselling House of Marionne series, which #1 bestselling author Alex Aster praises as "a sweeping fantasy brimming with magic, secrets, and romance."

The stunning first printing of Fortress of Ambrose will feature a gorgeous designed case and exclusive metallic endpapers!

With the future of the Order clouded in uncertainty, and the evil within its ranks coming to the surface, Quell Marionne has nowhere left to turn.

Everyone Quell cares about is gone and she still can’t escape the powerful legacy that wants to destroy her. But when she uncovers an earth-shattering revelation, she must choose: be the hero the magic world needs or save Jordan.

Meanwhile, a darkness festers inside Dragunheart Jordan Wexton. His path to survival means becoming the monster he was bred to hate, if he can overcome the power rotting within himself.

In a world where the line between proper and forbidden magic blurs, Quell and Jordan, along with two unlikely allies – bitter assassin Yagrin Wexton and magicless Heir Nore Ambrose, must navigate a treachero's path where freedom hangs by a thread. Can love tip the scales toward freedom? Or will rivalries and deadly betrayals shatter their hearts and destroy the world they once knew?