Emmaline Black has a secret. She can hear the rhythm of heartbeats. Not just her own, but others' too. It's a rhythm she's learned to control, and that can only mean one thing . . . Emma's a witch.

In a world where a sentence of witchcraft comes with dire consequences and all children who have reached the age of thirteen are tested to ensure they have no witch blood, Emma must attempt to stamp out her power before her own test comes. But the more she researches, the more she begins to suspect that her radically anti-witch aunt and mother are hiding something — the truth about their sister, her Aunt Lenore, who disappeared under mysterious circumstances years ago.

The day of the test comes, and Emma's results not only pair her up with strange new friends, but set her on a course to challenge everything she's ever been taught about magic, and reveal long-buried family secrets. It seems witches may not have been so easy to banish after all. Secret cities, untapped powers, missing family members — Emma is about to discover a whole new world.