Hedgewitch apprentice Wren has followed one rule her entire life: her hair can not be allowed to grow. Cutting it short keeps her safe, though her guardian has never explained who or what Wren must be kept safe from. But when Wren saves an outsider from the dark woods she calls home, her hair--and its strange, seductive magic--are released.

Before Wren can face the consequences of breaking her most important rule, she and her new companion Finn discover soldiers from Ilanthus attacking her village. To her horror, he confesses they are searching for him--and will destroy any witches they find along the way. With no one else to turn to, they agree to help each other escape. However, a dangerous desire fueled by magic burns between them, strengthening each time Wren uses her powers.

But when Wren discovers Finn has been hiding a dark truth about her past, she questions everything she thought she knew: Her guardian. Her magic. And the man she dreamed of sharing a future with.