An arms dealer with a heart problem is too ill to stand trial and taken to a teaching hospital for treatment. Dalgliesh questions him and tensions among the nurses and other medical staff start to be revealed.

Despite being present during the death of one of the student nurses, Dalgliesh is not asked run the investigation. Further relationships between the staff are revealed. Dettinger, the arms dealer, recognizes somebody from his past.

Dalgliesh starts to make progress despite the lies and evasions of the people who have been interviewed. Dettinger's final words, as told to his wife, reveal a dark past for one of the nurses.