Mastermind 2011/12 Episode 20 Episode 20 ( Air Date 2012-03-02 ) Genre Talk category. Overview "John Humphrys asks the questions as the hunt continues for the nation's Mastermind. Subjects are: the Coast to Coast Walk, pop music of the 1980s, the satirical works of William Hogarth and the life and works of Ralph Vaughan Williams.".