Mastermind 2019/20 Episode 15 Episode 15 ( Air Date 2019-12-30 ) Genre Talk category. Overview "John Humphrys presents another heat of the relaunched series of the classic quiz where contenders take the famous black chair under the glare of the spotlight and the ticking clock in an attempt to become the next Mastermind Champion. Tonight's specialist subjects are particle physics, the life and works of Douglas Adams, California and Carry On films.".