January 1975. Student nurse Heather Pearce dies during a training demonstration. Detective Chief Inspector Adam Dalgliesh is sent to investigate, accompanied by his partner DS Masterson. Pathologist Dr. Chopra confirms that Pearce was poisoned. Dalgliesh and Masterson take statements from the nurses, despite Matron’s attempts to intercede.

After Fallon’s death, Dalgliesh finds a library book in Fallon’s room and a letter in Pearce’s pigeonhole about a patient of Courtney-Briggs’ called Martin Dettinger, whose recent death on the hospital ward upset her. He later discovers rose spray, which Chopra confirms was used to poison Fallon. In the woods Dalgliesh is violently attacked.