This British spy drama has all the hallmarks of Zeitgeist cool - from stovepipe pants to a red soft-top Porsche – and is one of the many similar films such as The Ipcress File that were released during the the mid-60s James Bond craze.
Despite a Harold Pinter screenplay it is very much in the 007 style with an oddly-cast George Segal as the Secret Service agent Quiller who is called on by his superior, Pol (Alec Guinness), to infiltrate a Neo-Nazi gang in early 60s Berlin after two British agents have been killed on the same mission. But he is captured by the villains whose boss (Max Von Sydow) allows him to escape in the hope he will lead them to Pol.
Senta Berger provides the chick factor and spy-vs-spy shenanigans are provided by any number of stereotypical characters from both sides of the camp in what is a routine film that will find an audience with 60s style aficionados, and/or Nazi-movie buffs but that's about it.