Operation Crossbow (1965)

During WWII, the British government hears rumors that the Germans are developing a rocket technology that can cause mass damage to London. So they drop three undercover agents (George Peppard, Tom Courtenay, Jeremy Kemp) into Germany to infiltrate the factory building the rockets. Directed by Michael Anderson (LOGAN'S RUN), on the surface this may seem like a typical WWII adventure that were popular in the 60s like WHERE EAGLES DARE, THE DEVIL'S BRIGADE, THE BRIDGE AT REMAGEN etc. but it's a very well crafted and intelligent WWII thriller (Emeric Pressburger was one of its writers). To give it a sense of realism, all the actors speak German in the scenes in Germany when appropriate. There was an actual Operation Crossbow during WWII but the movie is a highly fictionalized depiction of that event. It's a gritty look with no concession to movie sentiment and two of its lead actors are shockingly killed. The film could have used some slight trimming but that's nitpicking. This is a thinking man's war adventure. The impressive cast includes Trevor Howard, John Mills, Lilli Palmer, Richard Todd, Richard Johnson, Paul Henreid, Anthony Quayle, Sylvia Syms, Helmut Dantine and John Fraser.