They say there's a vampire on the Northern Line.

For Ayesha Swanson, it's an everyday UKXD case. But when the trap goes wrong, and her daughter, Emilia, is kidnapped by the vampire, she, Mo, and Aimi find themselves in a dangerous game of inter-departmental politics, and a desperate, bizarre attempt at immortality.

Who is the neurotic Lovett Strange, tracking our heroes? And why is his Siamese cat, Lolly, directing his actions?

With Mo's loyalty in question as he falls in love with Strange, and Aimi stuck in the 1980s, forced to procure girls for the vampire, Ayesha must enter into a costly bargain with the slimy Mr Obscene to save her family.

Because blood's worth it, right?