The small city of Algonquin Bay in northern Ontario: A freak warm front has moved in, making it feel like April and rousing hungry bears from hibernation. So when Ivan Bergeron's dog brings him the chewed-off arm of a white male, it's assumed the victim met a natural if ugly end. Except, as it turns out, the owner of the arm was dead before the bears got to him.

Algonquin Bay is rocked by an unusual number of suicides, including the wife of Detective John Cardinal, but a string of hateful anonymous notes leads him to suspect that her death had been a homicide, despite the disbelief of his colleagues.