The three-alarm fire at a Chelsea, Massachusetts, apartment building was the state’s deadliest fire in more than two decades, leaving seven people dead, including two firefighters. Investigators said it was a simple accident, the fault of bad wiring. But one of the men who survived, Boston firefighter Jack McGee, blames an arsonist for the blaze. His finger-pointing soon makes him a pariah in the department, a traitor to some, and a kook to others. Two years after the fire, still haunted by the death of his friends, McGee takes the case to Spenser. Spenser quickly learns not only that McGee might be right, but that the fire might be linked to a deadly string of new arsons plaguing one of Boston’s oldest neighborhoods. As Spenser deals with some tough personal issues with longtime love Susan Silverman, he follows the trail of fires through a mire of corruption and greed while everyone wonders where the firebug will strike next.