Tom Mankiewicz's spotty adaptation of Jack Higgins's best-selling novel centres on a group of Nazi infiltrators bent on kidnapping Winston Churchill.

The action sequences (although late in coming) are first-rate in the capable hands of director John Sturges.

The two best performances - hardly surprising as the stars (Michael Caine, Donald Sutherland, Robert Duvall, Jenny Agutter) get the worst lines from Mankiewicz's variable script - come from one-time Upstairs Downstairs star Jean Marsh (as a German secret agent) and John Standing (as the parish priest).

If the film's twist opening seems vaguely familiar, that could be because the same device was used in Ealing's wartime drama Went the Day Well in the Forties.

Watch for the slip when Jean Marsh tells Judy Geeson that Churchill's to be kidnapped by the Germans, but then goes to the Americans and tells them it's an assassination plot.