A piercing scream, shattering the evening calm, brings Superintendent Adam Dalgliesh hurrying from his literary party to the nearby Steen Psychiatric Clinic, where he discovers the body of a woman sprawled on the basement floor, a chisel thrust through her heart. As Dalgliesh probes beneath the apparently unruffled calm of the clinic, he discovers that many an intrigue lies hidden behind the Georgian terrace`s unassuming facade. Professionally, he has never known the taste of failure. Now, for the first time, he feels unsure of his own mastery as he battles to unmask a cool killer who is proving to be his intellectual equal, and who is poised to strike again.