An obsession with a beautiful serial killer entangles a vampire hunter's daughter in an immortal sapphic romance in this mesmerising new gothic fantasy from the bestselling author of Lucy Undying.Anneke has a complicated relationship with her father, Abraham Van Helsing - doctor, scientist, and madman devoted to studying vampires - up until the night she comes home to find him murdered, with a surreally beautiful woman looming over his body.It soon becomes clear that her father isn't the only inexplicably dead body. So, obsessed with vengeance, and armed with the latest in forensic and investigatory techniques, Anneke puts together a team of detectives to catch her mysterious serial killer.But, for reasons even she can't explain, Anneke keeps some crucial evidence to herself: infuriatingly coy letters, addressed only to her, occasionally soaked in blood, and always signed Diavola. Devil. The obsession is mutual, and all the more dangerous for it.And the closer Anneke gets to her devil, the less sense the world makes. Could her father have been right all along? Could Diavola be something even more deadly than a serial killer? Because as Anneke unearths more of Diavola's tragic past, she suspects there's still a heart somewhere in that undead body.A heart that beats for Anneke alone.