When Richard Logan, the partner in a safe making firm,is found unconscious on an old deserted bomb site, he finds that he has no recollection of the last three weeks. Then he discovers that the private detective hired by his wife, has been found murdered and a safe that his firm installed in a large country house has been cleverly opened and the contents are missing. So with the help of his wife, he sets out to uncover the truth.
The DC5 appear in the "night club scene" and are shown mainly in the background for several minutes where they "mime" to several non-DC5 numbers. The DC5 line-up is Dave Clark on drums, Mike Smith on piano, Mick Ryan on guitar, Jim Spencer on flute and Rick Huxley on bass guitar.