Violets Are Blue by James Patterson (2001)

After the strange sidestepping into the heart-tugging 'Love Story' territory of his recent work, it's good news to find James Patterson back at what he does best - setting his detective Alex Cross (and the reader) a baffling mystery to solve. And this is quite Patterson's most bizarre outing yet, with vampirism (no less) mixed into the grisly narrative. Back again is the malign criminal mastermind of Roses Are Red, as dedicated as ever to confounding (and destroying) Cross. Alex is catapulted into a highly unorthodox investigation when a pair of San Francisco joggers are found dead, suspended by their feet, all the blood removed from their bodies. Further brutal slayings follow in California and on the East Coast. Alex, against his better judgement, begins to entertain the possibility of modern-day vampires, though he does not discount the notion of one of the many different religious cults that flourish in America. Working with Jamilla Hughes, a streetwise young detective from San Francisco, he finds that the solution to one mystery leads to another, even more impenetrable. Patterson, as ever, couches his narrative in very short cliff-hanging chapters and demonstrates his usual brisk manner with Cross's private life. Perhaps full enjoyment is guaranteed only if you're familiar with Roses Are Red (some loose ends from that book are tied up here) but this is still commanding stuff.