Art expert Fred Taylor is the agent for paranoid Beacon Hill collector Clayton Reed, a civilized man yet utterly ruthless collector. Fred supplies not only the brainwork, but the muscle, in their association. And from time to time, Fred either runs with, or outfoxes, the police.It is the cops, in fact, who plunge him into his latest detection (after Harmony in Flesh and Black and Man with a Squirrel) by inviting him into a grisly murder scene. A decapitated corpse has been found alongside an Italian religious painting of the 17th Century. The body is clearly for the moment that of a John Doe, but can Fred identify the painting? Its subject is "Christ in Agony."Though Reed warns Fred to stay away from the Baroque's fascination with martyrdom if he values his sanity, Fred is hooked by the mystery. Fighting a snowstorm paralyzing Boston, he researches the picture's provenance and establishes it is supposed to have miraculous properties. He also comes to suspect it makes up part of a colle