In a sprawling mansion filled with peculiar treasures, January Scaller is a curiosity herself. As the ward of the wealthy Mr. Locke, she feels little different from the artifacts that decorate the halls: carefully maintained, largely ignored, and utterly out of place. Then she finds a strange book. A book that carries the scent of other worlds and tells a tale of secret doors, of love, adventure, and danger. Each page turn reveals impossible truths about the world, and January discovers a story increasingly entwined with her own.

Tunuva Melim is a sister of the Priory. For fifty years, she has trained to slay wyrms – but none have appeared since the Nameless One, and the younger generation is starting to question the Priory's purpose. To the north, in the Queendom of Inys, Sabran the Ambitious has married the new King of Hróth, narrowly saving both realms from ruin. Their daughter, Glorian, trails in their shadow – exactly where she wants to be. The dragons of the East have slept for centuries. Dumai has spent her life in a Seiikinese mountain temple, trying to wake the gods from their long slumber.

Brie hates the Fae and refuses to have anything to do with them, even if that means starving on the street. But when her sister is sold to the sadistic king of the Unseelie court to pay a debt, she'll do whatever it takes to get her back—including making a deal with the king himself to steal three magical relics from the Seelie court.

Winter lasts most of the year at the edge of the Russian wilderness, and in the long nights, Vasilisa and her siblings love to gather by the fire to listen to their nurse’s fairy tales. Above all, Vasya loves the story of Frost, the blue-eyed winter demon. Wise Russians fear him, for he claims unwary souls, and they honor the spirits that protect their homes from evil. Then Vasya’s widowed father brings home a new wife from Moscow. Fiercely devout, Vasya’s stepmother forbids her family from honoring their household spirits, but Vasya fears what this may bring.

The Solaris Empire is one conquest away from uniting the continent, and the rare elemental magic sleeping in seventeen-year-old library apprentice Vhalla Yarl could shift the tides of war.