When I saw this film 56 years ago, I wondered: Is this serious? It actually almost grows quite serious gradually, but until clouds gather for a storm when everything seems to go wrong, it's great fun and a wonderful spying game comedy all the way, although the humour can be quite sinister and black - joking about death is not a thing you do for laughs. There are many wonderful actors here, and they are all excellent, it was surprising to see Eric Sykes as a professional murderer and quite snug about his profession, and David Tomlinson for once as a perfect villain. Trevor Howard dominates the film by his very sinister character behind a rather amused but perfect stiff upper lip, and Rod Taylor for once makes a great comic character as a genuine playboy falling by chance into the wrong profession, and almost getting burned for it. Wilfrid Hyde-White is a jovial spy-in-chief, and Akim Tamiroff has a wonderful although comically grotesque supporting role. There is naturally more fun in Monte Carlo than in London, but that's where the sinister chapter starts off. After that you will be on for a ride which no one, not even the players, can know how it will end, but even if it ends with any probable disaster, there will always be another beginning.