Players (Dicks novel) explained

Players is a BBC Books original novel written by Terrance Dicks and based on the long-running British science fiction television series Doctor Who. It features the Sixth Doctor and Peri meeting Winston Churchill during the Boer War and prior to the abdication of the would-be king Edward VIII. Flashbacks scenes feature the Second Doctor meeting Winston Churchill in 1915 during the First World War, these sequences serving as a partial prequel to Dick's subsequent novel World Game, which is set during Season 6B.