A stranger collapses on the lawn of Ashfordly Hall. He is called Mickey Todd and has been beaten up pretty badly, but is very reluctant to talk to the police. Later Nurse Cassidy sees a pregnant, young woman in the village, who also shows all the signs of a thorough beating, and patches her up. Is she the victim of the same assailant? At least she belongs to the same group of traveling hippies as he does. PC Wetherby is doing some private investigating of his own and discovers that his wife is having an affair. He takes it out on Lord Ashfordly's game keeper Frank Kelly who is found dead the next morning with his throat cut. But Kelly may also have had a clash with the hippies who falsely accused him of assaulting Mickey Todd. David has to fight the competition from another taxi company and also has problems with his own taxi. It turns out that his taxi was sabotaged, and Aunt Peggy is sure that the owner of the other company - Ma Barker - is behind it.