Lord Peter Wimsey investigates after the novelist Harriet Vane is accused of poisoning her former lover.
Lord Peter asks Miss Murchison to go undercover has a secretary at Norman Urquhart's law firm. She learns he was illegitimate and now paying for a nurse to care for his mother. Insp. Parker confirms Philip Boyes was definitely poisoned.
Lord Peter asks his secretary Miss Climpson to find out what Urquhart's nurse Miss Booth knows. Faking a seance Miss Booth admits that Urquhart has forged Philip Boyes Will to make him the sole beneficiary but can Lord Peter break him.
While on a walking tour of the West Country, Harriet stumbles on the body of a bearded man with his throat cut on a rocky outcropping near the sea.
Mrs. Weldon says she intended to marry dancer Paul Alexis and believes he was murdered. Lord Peter tells journalist Salcombe Hardy that the owner of the razor was the murderer. Peter and Harriet attempt to recreate Alexis last movements.
Old Pollock tells the police he sold Paul Alexis 300 gold sovereigns. Lord Peter and Harriet attempt to deal with his infatuation and her fragile state of mind. Looking for Mrs. Weldon's husband, Bunter has more questions than answers.
Peter and Harriet solve Paul Alexis coded letter and learn he was plotting to restore the monarchy to Russia. However his arranged meeting took place two hours before he died and witness Jem Pollock only saw Alexis meet with a young woman.
While Peter is on a governmental mission, Harriet attends a reunion at Oxford and is recruited to find the author of a rash of vicious poison pen letters there.
Harriet Vane continues her research into the odd goings on her old college. She is attacked and knocked unconscious while investigating someone playing the organ in the college chapel in the middle of the night.
The prowler evades Harriet but leaves hairpin. Peter is asked to look over the evidence but Harriet is left flat when he follows an inquiry without her. Miss Devine's tale of an academic faking his thesis points to someone with a grudge.