Police lieutenant Joe "Dart" Dartelli made one critical mistake in his police career. Three years ago, he chose to ignore a piece of evidence in a suicide case – a suicide that may have possibly been a murder – because the dead man was himself a vicious woman-killer who more than deserved his fate. And the evidence that Dart ignored could have raised difficult questions about his former mentor, the brilliant forensic specialist Walter Zeller.

But another suicide victim turns up – the body of a wife- beater – and Zeller has disappeared off the face of the earth. With nothing to tie the deaths together except some strange blood chemistry – and clear evidence that the death was self-inflicted – the case is officially closed. Dart knows that what’s best for him is just to let things lie. There’s no proof; only two unrelated suicides. Cleared cases. But Dart knows in his deepest heart that Zeller is on some twisted vigilante crusade. And it’s going to happen again. And only Dart can stop it.