Maple Arcand's a witch. A half-moon witch with wonky magic, friends who are few and far between, and a non-existent love life. But Maple's going to change all that, just so long as she can get her magic to work. But when Ronin-a self-proclaimed good vampire-shows up and tells Maple that he needs her to close a wayward door between The Deep and The Mid, everything Maple believes about herself is put to the test. Maple's a good person, a good student, and a good witch. She wants to help Ronin and stop the errant demons from killing innocents, but to do so, she'll need to use dark, forbidden magic. The more Maple learns from Ronin, the more she realizes she's been kept in the dark. But black magic isn't something she wants to use, even if it will stop the demons. Yet Ronin insists it's the only way. Maple's sure she can't be what the vampire says he needs, no matter what hangs in the balance. Even if it's life itself. Can she?