Michael Caine gives a full-bodied performance as a middle-aged Briton seeking the truth about the mysterious death of his son (Nigel Havers), who worked as a Russian translator at the top-secret intelligence centre, the Government Communications Headquarters (GCHQ).
Caine is tremendously convincing as the Korean War veteran (which he is in real life) who now feels betrayed by his country, as his search leads him along the corridors of power peopled by such posh types as James Fox and John Gielgud.
Eschewing the usual thrills, the picture creates a totally plausible and undeniably creepy world of whispers and a seemingly impenetrable wall of class privilege and secrecy.
Unfortunately, the ending is somewhat weak in contrast to the intrigue that steadily builds throughout the film.
Sir Adrian Chapple