It is two thousand long years into the future. There is no more Earth. There is only Callistra. Since the conclusion of the fae civil war that decimated the human population, there has been a strained peace among the surviving mythical creatures. But now, a strange fae illness is spreading across Callistra, and the era of harmony is crumbling fast. Pasiphae of Eo has been framed. Her grandmother, the most powerful witch in Eo, has fallen sick, and Pasiphae is suspected to be responsible. Forced to flee her homelands for treason against her coven, the only way to clear her name is to find the true traitor. Pasiphae has no choice but to venture deep into unknown territory with help from one of the fae. He can help her find the cause of the illness from within the Unseelie Court, where the walls talk and the shadows move, and she can do for him what the fae cannot do themselves: lie. But a conspiracy is unravelling in this foreign land swathed under perpetual night. All Pasiphae wanted was to prove her innocence, but within the heady darkness of the malevolent faery court, there is love and betrayal so potent it could ruin the world a second time.

In the sequel to Treachery Queen, the Seelie Court has declared its war on the world, and nothing will ever be the same. It has only been a week since Pasiphae of Eo entered a fake marriage alliance with the Seelie Crown Prince in a bid to forestall his mother's coming invasion on Medeis, Pasiphae's homeland. Now, those who were once enemies have disappeared into the shadows, while new contenders have clawed their way into power. Amidst the chaos, there is only one possible outcome that ends well for Medeis: Seth must have the Seelie throne, and Pasiphae takes it upon herself to ensure it. Meanwhile, Circe of Eo has turned diplomat. The Unseelie Queen knows that invasion is coming, and is desperate to snatch the Isles, where the humans make their home. To keep it from her grasp, the witches must conquer the land first, for the humans' own good. But the Isles has secrets of its own, and if Circe isn't careful, she may be swallowed by the rising tide. From a perilous journey into a country that kills all who enter, to a mission into the Seelie Court during its midnight sun, the two sisters will do anything to protect Medeis. Heads will roll, hearts will be broken, and if the world is to fall a second time, then so be it.

The world is at war, and in the third instalment of the Treachery Queen series, it is life or death with every turn. Pasiphae of Eo has made too many enemies to count, but she is untouchable. As the queen of Airesi and the face of Medeis, there is no other witch with a name that strikes the fear which hers does. If only Callistra knew the truth: Pasiphae of Eo has no true magic, and with the closer battle looms, the ruse is starting to feel more and more fragile. But Pasiphae has bigger problems. The countries of Callistra have melded together. Borders are no more. As Morgana resumes her upward march from Khotadi in her bid to consume the world into the Unseelie Court, Pasiphae and Seth must push back with their joint Seelie and witch forces. To do so, Circe of Eo must first unite the witches, who are more torn than ever between differing ideals. As if that were not enough, the humans in Calva have fractured into two and the undines who occupy the seas surrounding Callistra are stirring with a dangerous sort of hate and revenge. The opposing side is growing. Before the sisters of Eo can fight a war, they must understand Morgana's power, and when a revelation sends Pasiphae and Circe into all corners of the land, everything about Callistra that they once knew will be questioned.