It's hot.

The snow is gone, the ice is gone — winter is long forgotten. When the phone wakes Phil Broker at five a.m. on the morning of his forty-eighth birthday — six months removed from his surviving a January cold snap that (in Absolute Zero) nearly claimed his life — it's already ninety-two degrees. It's July, and Stillwater, Minnesota, finds itself in the middle of the worst heat wave in local memory.

The news on the phone has nothing to do with birthday wishes, however. A year earlier, an angry citizen served as jury and executioner by pumping twelve bullets into a known pedophile — and in the process became a folk hero, dubbed "the Saint" by locals. Despite protests to the contrary, everybody in the community (including the police department) felt justice had been served, and the investigation quickly went cold. Ever since, strong rumors have circulated that the real reason the Saint hasn't been apprehended is that he — or she — is a cop.

Now a priest has been murdered, and a clue left at the scene suggests it to be the work of a vigilante. Was the priest a sexual predator? Could the Saint be back? For the members of the Stillwater law-enforcement community, it means that a killer could be in their midst.

The caller begs for Broker's help: as an outsider, Broker can be counted on to follow the investigation wherever it leads. But as the temperature mounts and new victims begin surfacing, Broker wonders if he's been set up to catch a bullet for a scandal that threatens to bring down the Stillwater Police Department.