The film has suspense , tension , emotion , mystery and specially in its final a little bit of violence . Following the death of his son , in the Austrian Alps , ¨The Key Man¨ , a high ranking officer in the CIA called Dan Slater (Yul Brynner) , has to face off the most daring plot ever concocted by the secret agents of two worlds : East and West , during the Cold War . In Austria he decides to investigate and step by step finds out that the death of his son was no a skiing accident . A retired , prior undercover operative , Frank Wheatley (Clive Revill) , whom he had hoped would watch out for his son helps Dan seeks out the real killers . By the way , Dan meets socialite Gina (Britt Ekland , though Ulla Jacobsson was offered first this role) , the companion of rich and mature Mrs. Carrington (Moira Lister) , who puts him on the alright trails o perhaps fake clues . Eventually , rare inconsistencies begin appearing leading Dan to conclude that Russian secret service led by Col. Berthold (Anton Diffring) attempting a mysterious kidnapping .
Suspenseful movie packs thrills , intrigue , frantic action , twists and turns . This complex piece of espionage is notable for its snow-capped scenery and its thrilling intrigue from start to finish . Interesting as well as amusing screenplay from Alfred Hayes and Frank Tarloff based on Henry Maxfield's novel titled "Legacy of a Spy". However , the movie's script was similar to the then recently released Spy with my face (1965) and its TV counter-part The agent of T.I.A. : The Double Affair (1964) . Although the picture has various ingredients for entertainment , the screenplay is also complex , including inexplicable incidents , the plot has gaps , in spite of it results to be pretty fun . Nice acting by Yul Brynner as cold and emotion-less agent , a top-notch performance who steals the show and gorgeous Britt Ekland's first major movie role . Support cast is pretty good such as Lloyd Nolan as Major Edwards who assigns him the dangerous mission , Clive Revill as undercover agent , Moira Lister as wealthy Mistress and Brandon Brady as Russian agent . Special mention for Anton Diffring in his ordinary German face and cool , clipped diction , as he replaced an actor who dropped out ; here Anton plays magnificently a Russian operative who attempts to substitute starring with a double of its own in order to obtain a mole in the highest echelons of the CIA agency . Diffring was a character actor who worked continuously in movies due to his aristocratic style , making him ideal for typecasting in British and later American films as Nazis and other vile , despicable roles , what was ironic about his typecasting as a Nazi is that he fled Nazi Germany in 1939 .
Lively and enjoyable musical score by Ernie Freeman , including catching sounds throughout . Colorful cinematography by Dennis Coop , shot on location in wonderful outdoors as the mountain range vista seen in the film is the Tyrolean Alps situated in the state of Tyrol in western Austria . Good aerial scenes and spectacular snowy landscapes carried out by the late aerial cameraman John Jordan who died whilst working on Catch 22 (1970) . It was released before the snow-laden James Bond movie On her Majesty's secret service (1969), Jordan worked on both these spy movies . Lavishly produced by Hal E Chester , he was a juvenile actor , then a producer of low-budget movies in Hollywood, before he moved in 1955 to Britain, where he set up his own production company to take advantage of the lower costs of filming ; over the next 15 years he turned out a wide range of pictures, which often featured American stars such as Mickey Rooney, Dana Andrews, Paul Newman and Yul Brynner . The picture was well directed by Franklin J. Schaffner . He made excellent motion pictures such as "The Planet of the Apes", "Patton, " "Papillon" , ¨"Nicholas and Alexandra" , after the flop of his film titled " Islands in the Stream ", in which went on to coincide with the actor of "Patton" , George C. Scott , he decided to embark on a project more commercial and successful as "The Boys From Brazil" ; however , ¨Sphinx¨ ,¨Lionheart¨, ¨Si Giorgio¨ were other box office failures . Rating : Better than average , worthwhile watching .
