It's been a wild year for Sideways Pike. After forming a coven with the three most popular girls in school and developing a huge crush on a mysterious stranger named Madeline, Sideways' Halloween was ruined by finding out that Madeline wasn't trying to make out with her, but to steal Sideways' specter, the force that gives witches the ability to cast magic spells. From Madeline's perspective, it's not her fault: after a doomed relationship with one of the creepy near-identical Chantry Boys turned into a witch hunt, they took her specter, so, really, she's only borrowing Sideways' until she can recover her own and punish the Chantrys.

The specter-less Sideways is in a horrid, distracted mood, unable to do magic and with part of her consciousness tied to Madeline's, on the lam as she uses Sideways' specter to hunt Chantrys. The other Scapegracers are much jollier, heading into the winter holidays having set up shop as curse crafters for girls in their school who've been done wrong by guys. When Sideways—through Madeline—gets a flash of how to track down both her foes at once, she asks the Scapegracers to help entrap them, only to be told her plan is unsafe and unwise. So if she's going to find Madeline, her only ally is Mr. Scratch, the inky book demon currently inhabiting her as life support until she gets her spectre back.

Sideways is used to being an outcast loner, and is desperate to do magic again, so she's not going to let little barriers like facing an betraying crush and a family of six demented witch hunters practically alone stop her. But she and her trusty stolen bike are in for a bumpy ride...