Starring Barry Jones, Olive Sloane, Sheila Manahan

When the Prime Minister receives a letter, signed by an eminent nuclear scientist, threatening to blow up Parliament, it is at first dismissed as a hoax. But then the scientist disappears - and a bomb that could devastate London is stolen.
Tension mounts rapidly in the desperate search to find both scientist and bomb before the 'seven days' time limit runs out.
(This Week's Films: page 11)