Hugh Bonneville and Samuel Barnett who appear as the Police Inspector and his Sergeant, appeared together two years later in the BBC comedy series "Twenty Twelve" as Ian Fletcher, head of Deliverance for the 2012 London Olympics, and his PA Daniel Stroud.
The trivia item below may give away important plot points.
The secret that is revealed at the end bears a strong resemblance to the real-life story of movie star Gene Tierney's daughter, Daria. During World War Two, while she was pregnant, Tierney made an appearance at the Hollywood Canteen, where members of the Allied military got to mingle with celebrities. Shortly afterward, she became ill with German Measles (Rubella) and later gave birth prematurely to Daria, who was deaf, partly blind, and severely mentally disabled. Tierney was obliged to institutionalize Daria, and the star had a mental breakdown which led to several of her own stays in mental hospitals. Years later, a woman approached Tierney and bragged that because she was such a big fan of Tierney's, she had broken her Rubella quarantine during the war and snuck off base to attend Tierney's night at the Hollywood Canteen. Tierney, already mentally unstable, was inconsolable at the idea that her own popularity and fame had caused her daughter's severe disabilities.