Written by Francis Durbridge and Charles Hatton.
[Starring] Jack Hedley as Tim Frazer
Starring Ralph Michael, Michael Aldridge with Francis Matthews, Patricia Haines

Tim Frazer is trying to discover the identity of 'Ericson', the head of a diamond smuggling organisation. During his investigations Frazer is mistaken for a friend of Ericson's and is instructed to visit a certain Mr. Gordon Dempsey. Dempsey questions his visitor and finally, to Frazer's amazement, produces a metronome.