In this fourth episode of Clive King's children's classic, a policewoman follows Barney to Stig's cave in the quarry. She tells Barney's grandfather it is not safe for Barney to be at the quarry. Barney overhears and rushes back to the cave to run away with his friend, but Stig is nowhere to be seen.
'Harry Enfield's Big Arts' (BBC 1, 7.30 to 8pm)
This programme previews the first-ever Big Arts Week on 15 to 22 June, which aims to get children and young people involved in the arts. Young artists and primary and secondary schools can register for Big Arts Week by calling freephone 0800 888 809 between 3 and 10 February or by logging on to the website www.bbc.co.uk/timebank.
'How to Build a Human - Forever Young' (BBC 2, 9 to 9.50pm)
This final programme in the series about the way our genes and hormones shape us from cradle to grave explains how the solution to ageing may be in sight. If scientists can solve why some animal species live for so long, they may be able to identify the genes that prolong life, enabling future generations to re-engineer the body so protection against ageing is inbuilt from birth.
'Panorama - MMR: Every Parent's Choice' (BBC 1, 10.15 to 10.55pm)
The current affairs programme examines one of the fiercest medical debates of recent times and tells the stories of three families convinced that their children developed autism as a result of their MMR jabs. It asks what steps the Government can take to stop the decline in MMR vaccinations.
4 February 'Clubs' (BBC Radio 4, 3.45 to 4pm each weekday)
A celebration of the great children's clubs of the 1950s, 1960s and 1970s - the Puffin Club, the Young Ornithologists Club, the I-Spy Club, the Chalet Girls Club and the Famous Five Club - hearing from former members.
5 February 'Life as a Child' (BBC Radio 4, 9 to 9.30pm)
Connie St Louis interviews children aged five to 11. This second programme in the series follows children into school, and finds out how they learn to 'play the game' while trying to work out what the game is.
'File on 4' (BBC Radio 4, 8 to 8.40pm)
Britain has 110,000 people who have been convicted of sex offences against children. The Probation Service is meant to oversee their treatment, but provision is patchy and most offenders receive no help. This programme asks if we are missing the chance to prevent thousands of crimes.
7 February 'The Trust - Children's Ward' (Channel 4, 9 to 10pm)
This fourth programme in a five-part series about the work of Nottingham's Queen's Medical Centre focuses on the ward for acute brain disorders.
'Bitter Inheritance' (BBC 2, 9.50 to 10.30pm)
A look at the genetic condition Huntingdon's Disease, which attacks the brain and central nervous system.
