Plot: Middlesex Polytechnic at Trent Park in North London is the setting for this third semi-final. Kevin Perkins (contracts liaison officer) The Novels of Agatha Christie; Tom King (freelance writer) The History of Gardens and Gardeners in Britain (1500-1939); Margaret Fleming (tax inspector) The Smiley Novels of John le Carre; Keith Harrison (schoolteacher) The History of the Roman Empire AD 180-337