Nemesis

S3, E4: Miss Marple is faced with her greatest challenge yet when she receives instructions from an old friend, the recently deceased Mr Rafiel, to investigate a 'possible crime'. But there's a catch - she has not been told what the crime is. Instead, she is booked onto a mystery coach tour to gather clues. Miss Marple takes her nephew Raymond West to accompany her on the tour as Mr Rafiel warns that danger may threaten. It begins to dawn on them both that all the passengers are connected to a young girl, Verity Hunt, who went missing during the war. They also realise that every destination on the tour is significant and start to piece together information about Verity. Why did she flee from a nun's sanctuary in the dead of night to be with her German lover, Mr Rafiel's son Michael, and was never seen again. With the help of young detective Colin Hards, Miss Marple and Raymond piece together the secrets of the past to fulfil a promise to her dear old friend.