The thrilling conclusion to #1 New York Times bestselling author V. E. Schwab's beloved world of parallel Londons—now at the brink of collapse. Loyalties will be tested, and sacrifices will be made...

As darkness sweeps the Maresh empire, the once-precarious balance of power among the four Londons has reached its breaking point.

Now, as an ancient enemy returns from another world to bring chaos and decay, friends and foes must unite in a desperate race to save themselves from the end of the world.