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John Humphrys asks the questions as another four famous faces brave the black chair. Tonight's contenders and specialist subjects are BBC Watchdog presenter Michelle Ackerley on classic TV series Columbo, The Wine Show expert Joe Fattorini on the line of longitude two degrees west, Instant Gardener Danny Clarke on Sir Garfield Sobers and comedian John Finnemore on the ghost stories of MR James.
Other episodes for this season
