Mystery novelist Harriet Vane, recovering from an unhappy love affair and its most unpleasant aftermath, seeks solace on a barren beach deserted but for one notable exception: the body of a bearded young man with his throat cut. From the moment she photographs the corpse, which soon disappears with the tide, she is puzzled by a mystery that might easily have been a suicide, a murder, or a political plot. With the appearance of her dear friend Lord Peter Wimsey, however, Harriet finds yet another reason to pursue the mystery, as only the two of them can pursue it.