Rupert and Jocelyn Middleton’s daughter Vivienne has gone missing, and Pc Joe Mason goes to investigate. Rupert and Jocelyn admit that, having returned home late from supper at Ashfordly Estate, they assumed that Viv was staying with her friend, Helen, but Helen says she hasn’t seen Viv since the previous afternoon.

The Middletons tell Mason that they think Viv’s American boyfriend Bobby is a bad influence, and Rupert is adamant that Bobby only wants to marry Viv to avoid the Vietnam War draft. Mason believes that the Middletons’ dislike of Bobby is the reason behind Viv’s disappearance.

The next day, Mason goes to visit Bobby, who tries to get away on his motorbike when he spots Mason’s police uniform. Mason finally catches up with Bobby, who admits that he fled because his visa had expired. Bobby insists he has nothing to do with Viv going missing. But is he telling the truth?

Elsewhere, Peggy gets excited when David finds an old metal detector, dreaming of the buried treasure they might find. When a number of valuable bronze statues are stolen, and David’s van is spotted outside a local scrap yard, police suspect that Peggy and David may be involved is something more serious than just looking for artefacts.