Croydon Social Services have a problem: there are over 200 old people in Kingsfield and not enough people to help them. So the headmistress of Kingsfield Comprehensive starts a 'Helping Hands' programme: "You will be old one day, too," she tells her pupils, "so think carefully before you say 'no'."

The volunteers from Class 5B enjoy their social work and find out a lot about the problems of the old people in their neighbourhood. One of the biggest problems is a series of burglaries. The burglars seem to have 'inside information'. Who is helping them? Is it Mrs Brown, one of the 'home helps'?

When Dr Rao is brutally attacked and robbed, the 'Helping Hands' become detectives. When Peter finds a footprint of a SWIFT trainer under Dr Rao's kitchen window, he begins to think that one of the burglars may even be a boy in his class at school...