Where Eagles Dare (1969)

Synopsis
An expensive but enormously profitable war picture, Where Eagles Dare centers upon a daring rescue and even more daring escape. Disguised as Nazi officers, commandoes Maj. John Smith (Richard Burton), Lt. Morris Schaffer Clint Eastwood and six other courageous souls parachute behind enemy lines. Their mission: to rescue an American general, held captive in a supposedly impenetrable Alpine castle. Aiding and abetting the commandoes are Allied undercover agents Mary (Mary Ure) and Heidi (Ingrid Pitt). Also on hand is a British officer (Patrick Wymark), who masterminded the mission. Somewhere, somehow, someone amongst the Allies is going to turn out to be a traitor. There's also a neat plot twist in store when the commandoes manage to reach the American general -- which leads to yet another twist. The vertigo-inducing climax has made Where Eagles Dare one of the most sought-after of "early" Eastwood starring features. The film was written directly for the screen by espionage novelist Alistair MacLean. ~ Hal Erickson, All Movie Guide