Fred MacAulay, Mark Billingham, Georgia Henshaw, Charles Collingwood

John Humphrys presents the celebrity version of Britain's toughest quiz. Four more celebrities take on the Mastermind challenge as comedian Fred MacAulay, crime author Mark Billingham, actress Georgia Henshaw and The Archers' Brian Aldridge - Charles Collingwood - answer questions on the sitcom Porridge, Elvis Costello, TV series Sherlock and Hampshire County Cricket Club.