
When a young secretarial student dies suddenly at home, Endeavour senses that there is more to the case than the initial verdict of heart attack.

A new kind of killer haunts the Oxford twilight - he appears to strike at random, but Endeavour uncovers an underlying method to the staging of the crimes.

When a worker at a missile factory is murdered, Bright wants the case resolved, but Endeavour remains unconvinced that the crime is such an open-and-shut case.

As the shadow of East End villainy falls on Oxford, a hit-and-run accident claims the life of a professor. Endeavour and Thursday must each face their pasts.