When an Austrian nobleman offers a substantial donation to the University of Oxford, Charles Maddox is called on to investigate the generous benefactor. It is a decidedly mundane task for the increasingly renowned criminal investigator, but Maddox welcomes the chance to trade London s teeming streets for the comforts of a castle in the Viennese countryside. Comfort, however, is in short supply once Maddox steps onto foreign soil and into the company of the mysterious Baron Von Reisenberg.

Owing to a string of gruesome murders committed by an elusive predator branded the Vampire, London is on the verge of widespread panic. But there's little doubt in Maddox's mind who is responsible. And whether his enemy proves merely mortal or something more Maddox must finally end the monstrous affair . . . before more innocent blood is spilled.

The chapters about Charles' investigation are sandwiched between chapters from the journal of Lucy, a young woman from Vienna who helps her father with occult shows in the theatres of Europe. Although at first the two parts of the story seem unrelated, the author manages to wind it all together at the end.