From New York Times bestselling and Hugo Award-winning author T. Kingfisher comes a dark retelling of the Brothers Grimm's Goose Girl, rife with secrets, murder, and forbidden magic.

Perfect for fans of Naomi Novic, Alix E. Harrow and Nettle & Bone.

Cordelia knows her mother is unusual. Their house doesn't have any doors between rooms―there are no secrets in this house!―Cordelia isn't allowed to have a single friend. Unless you count Falada, her mother's beautiful white horse. The only time Cordelia feels truly free is on her daily rides with him.

But more than a few quirks set her mother apart. Other parents can't force their daughters to be silent and motionless―obedient―for hours or days on end. Other mothers aren't . . . sorcerers.

Willow is in need of an escape.

A former sitcom star, she’s been publicly shamed on the internet after posting something she really shouldn’t have.

She checks in to Camp Castaway, an adults-only retreat based at an old campground in the woods.

It’s the first night and the campers gather round the fire to tell some ghost stories. That’s when Willow hears the tale of Knock Knock Nancy. A local urban legend about a witch, brutally beheaded in this very woodland.

They say her restless spirit knocks on doors late at night. If you answer, she’ll take your head.

Willow doesn’t believe in ghost stories. But the next day, a camper has vanished under mysterious circumstances. And then that evening, in her cabin, Willow hears it . . . .

Knock, Knock, Knock.