An elderly Sherlock Holmes retires to a seaside farmhouse in the aftermath of the Second World War, and struggles to cope with his diminished faculties. Assisted by his housekeeper's inquisitive son, he tries to piece together the events of the one case that he failed to solve. Period mystery based on Mitch Cullin's novel A Slight Trick of the Mind, starring Ian McKellen, Laura Linney and Milo Parker