A respected, dying Oxford don, husband of Morse's former fiancée, apparently shoots himself, but his doctor asserts that he was not capable of firing a gun.
When a serial killer is murdered in prison, his deathbed confession disavows one of the murders he had previously confessed to. Morse wants to reopen the case.
While Morse is in hospital for a bleeding ulcer, he takes an interest in an 1859 murder and becomes convinced its resolution was a miscarriage of justice.