A thriller in six parts by Victor Canning.
Starring Terence Longdon, Isobel Black and Peter Vaughan
with Peter Arne, Hamilton Dyce, Noel Johnson and Yootha Joyce
Raikes, planning a vast diamond haul for the Tintoc crime syndicate, is unaware that his assistant Sandra is reporting to the mysterious Pyramid organisation.
(Repeated on Friday at 9.5 p.m.)