Derek Turnbull

Derek Turnbull is a non-canonical character created for the 2009 ITV adaptation of Nemesis. He is the solicitor of Amanda Dalrymple and her companion on the "Daffodil Mystery Coach Tour" which Jason Rafiel had arranged for Miss Marple. Derek Turnbull is portrayed by Adrian Rawlins.

Jason Rafiel had asked Miss Marple to solve a possible crime or put right an unknown injustice. Through the course of events in the tour, it becomes apparent that the crime or injustice has to do with the fate of a young girl named Verity Hunt. It also becomes apparent that all the passengers in the bus (which Rafiel contrived in various ways to bring on to the tour) are somehow linked to the girl.

Derek's link is only clear towards the later of the episode and has to do with Sydney Lumley, Verity's former landlord who wanted her to marry him, and his later wife Margaret Lumley who looks very much like Verity. Not long before the events in the episode, Amanda Dalrymple had taken action to declare Verity legally dead as she had already disappeared for many years. This would clear the way for Amanda to inherit the estate of Lord Forrester once Verity, his only natural offspring is out of the way. Sydney Lumley heard about this and conspired with his wife Margaret to exploit her resemblance to Verity. She would pretend to be Verity in order to blackmail Amanda. Amanda had sent Turnbull with a photo and a list of questions about Verity to verify the claim, but Sydney was able to coach Margaret in giving the right answers since he know a fair bit about Verity's background. It would appear that Turnbull was taken in at first and Amanda ended up paying some money.

However, during the tour, Turnbull recognised Margaret during the hike at Bonaventure Rocks. He saw through the deception but offered to keep quiet about it if she would grant him favours. Margaret pretended to agree and Turnbull came to her room in the night but unfortunately for him, Sydney was there waiting for him and he ended up with a bleeding nose.