Morse and the team are called to investigate the murder of a taxi driver found dead in his cab on the outskirts of Oxford, and worry that a recent string of assaults on cab drivers has escalated to murder. As the inquiry unfolds, the detective finds the case hits too close to home and starts to retreat from those close to him.

It is the winter of 1971 and the team is split up by a snowstorm while investigating the murder of a college don, and Endeavour is stranded at an abandoned hotel where he becomes the subject of a revenge plot.