It's the third of six semi-finals of Britain's toughest quiz. John Humphrys invites four of the country's cleverest brains to take the lonely walk to the black chair where they will battle it out for a place in the Grand Final and move a step closer to becoming Mastermind 2004.

Specialist subjects are: Historical Buildings of England, Zulu War 1879, British Murders and Murderers 1850-1950, The Adventures of Tintin by Herge. Show less