It has been a year of change since Gemma Doyle arrived at the foreboding Spence Academy. Her mother murdered, her father a laudanum addict, Gemma has relied on an unsuspected strength and has discovered an ability to travel to an enchanted world called the realms, where dark magic runs wild. Despite certain peril, Gemma has bound the magic to herself and forged unlikely new alliances.

Now, as Gemma approaches her London debut, the time has come to test these bonds. The Order - the mysterious group her mother was once part of - is grappling for control of the realms, as is the Rakshana. Spence's burned East Wing is being rebuilt, but why now? Gemma and her friends see Pippa, but she is not the same. And their friendship faces its gravest trial as Gemma must decide once and for all what role she is meant for.