It's been 297 days since David died - and came back. He may have survived the avalanche, but the aftermath has been far worse. His wife moved out, taking his son with her, and a devastated David hasn't left his house since, terrified of the mysterious new power that followed him home from the ill-fated expedition. After months in seclusion, David's ready for a fresh start, and ventures out, determined to keep his power in check. But David's power isn't the one he needs to worry about.

Once, there were four worlds, nestled like pages in a book, each pulsing with fantastical power and connected by a single city: London. Until the magic grew too fast and forced the worlds to seal the doors between them in a desperate gamble to protect their own. The few magicians who could still open the doors grew more rare as time passed and now, only three Antari are known in recent memory—Kell Maresh of Red London, Delilah Bard of Grey London, and Holland Vosijk, of White London.

Olivia Prior has grown up in Merilance School for Girls, and all she has of her past is her mother’s journal—which seems to unravel into madness. Then, a letter invites Olivia to come home to Gallant. Yet when Olivia arrives, no one is expecting her. But Olivia is not about to leave the first place that feels like home; it doesn’t matter if her cousin Matthew is hostile, or if she sees half-formed ghouls haunting the hallways.

Kell is one of the last Travelers - magicians with a rare, coveted ability to travel between parallel universes. As such, he can choose where he lands. There's Grey London, dirty and boring, without any magic, ruled by a mad King George. Then there's Red London, where life and magic are revered, and the Maresh Dynasty presides over a flourishing empire. There's White London, ruled by whoever has murdered their way to the throne. And once upon a time, there was Black London...but no one speaks of that now.

Touraine is a soldier. Stolen as a child and raised to kill and die for the empire, her only loyalty is to her fellow conscripts. But now, her company has been sent back to her homeland to stop a rebellion, and the ties of blood may be stronger than she thought. Luca needs a turncoat. Someone desperate enough to tiptoe the bayonet's edge between treason and orders. Someone who can sway the rebels toward peace, while Luca focuses on what really matters: getting her uncle off her throne.

Kate Harker and August Flynn are the heirs to a divided city - a city where the violence has begun to breed actual monsters. All Kate wants is to be as ruthless as her father, who lets the monsters roam free and makes the humans pay for his protection. All August wants is to be human, as good-hearted as his own father, to play a bigger role in protecting the innocent - but he's one of the monsters. One who can steal a soul with a simple strain of music.

Oliver Marks has just served 10 years in jail - for a murder he may or may not have committed. On the day he's released, he's greeted by the man who put him in prison. Detective Colborne is retiring, but before he does, he wants to know what really happened a decade ago.

Ambrose wakes up on the Coordinated Endeavor with no memory of a launch. There’s more that doesn’t add up: evidence indicates strangers have been on board, the ship’s operating system is voiced by his mother, and his handsome, brooding shipmate has barricaded himself away. But nothing will stop Ambrose from making his mission succeed—not when he’s rescuing his own sister.

The Alexandrian Society, caretakers of lost knowledge from the greatest civilizations of antiquity, are the foremost secret society of magical academicians in the world. Those who earn a place among the Alexandrians will secure a life of wealth, power, and prestige beyond their wildest dreams, and each decade, only the six most uniquely talented magicians are selected to be considered for initiation. Enter the latest round of six: Libby Rhodes and Nico de Varona, unwilling halves of an unfathomable whole, who exert uncanny control over every element of physicality.

The emperor's reign has lasted for decades, his mastery of bone shard magic powering the animal-like constructs that maintain law and order. But now his rule is failing, and revolution is sweeping across the Empire's many islands. Lin is the emperor's daughter and spends her days trapped in a palace of locked doors and dark secrets. When her father refuses to recognise her as heir to the throne, she vows to prove her worth by mastering the forbidden art of bone shard magic.