Oddny and Gunnhild meet as children in tenth century Norway, and they could not be more different: Oddny hopes for a quiet life, while Gunnhild burns for power and longs to escape her cruel mother. But after a visiting wisewoman makes an ominous prophecy that involves Oddny, her sister Signy, and Gunnhild, the three girls take a blood oath to help one another always. When Oddny’s farm is destroyed and Signy is kidnapped by Viking raiders, Oddny is set adrift from the life she imagined—but she's determined to save her sister no matter the cost.

When Finlay Ashowan joins the staff of the King and Queen of Daxaria, he’s an enigma. No one knows where he comes from or how he came to be where he is, which suits Fin just fine. He’s satisfied simply serving as the royal cook, keeping nosy passersby out of his kitchen, and concocting some truly uncanny meals. But Fin’s secret identity doesn’t stay hidden for long. After all, it’s not every day a house witch and his kitten familiar, Kraken, take to meddling in imperial affairs.

Piranesi lives in the House. Perhaps he always has. In his notebooks, day after day, he makes a clear and careful record of its wonders: the labyrinth of halls, the thousands upon thousands of statues, the tides that thunder up staircases, the clouds that move in slow procession through the upper halls. On Tuesdays and Fridays Piranesi sees his friend, the Other. At other times he brings tributes of food to the Dead. But mostly, he is alone.

Librarian Sylvia Ashe knows nothing about her past, having grown up without a father and a mother who refused to discuss him. When she stumbles upon a diary that suggests she's descended from magicians, she's skeptical. After all, magicians are special, and she's just an ordinary woman who loves books. She seeks answers from a member of the most prominent family of magicians, but she quickly learns that finding the truth won't be easy, especially when he turns out to be as artless as her, and more compelling and dangerous than books.

Nothing is trickier than the truth. All Loki the trickster god of Asgard wants is a peaceful life where he's free to stir up a bit of harmless mischief. But when he's struck by a painful vision of blood, ash, and death he knows his fun has run out. Refusing to have his life obliterated by some stuffy prophecy, Loki feels he must save Asgard. Except the gods stand in his way. They don't trust the God of Lies, which means his only hope is to return to Odin, the man he wished to forget thanks to their complicated history.