The Falcon and the Snowman is the true story of two college-age rich kids from L.A. who become spies for the Soviet Union. One, played by Penn, is already a drug smuggler up to his eyeballs in trouble. The other, played by Hutton, lands a position at an aerospace firm where his job is to man a top-secret cable facility. There he learns of some of the dirty tricks employed by the CIA on foreigners that America doesn't like. Don't forget that the movie is set the early 70s, the time of Vietnam and Watergate. Appalled at what he's learned, the Hutton character decides to betray his country and convinces his buddy to join him. Neither of them is long on brains, it is not long before they're way in over their heads with no way out.
This is not a thriller, and is rather slowly paced. If this is not a problem for you, then it is well worth the rental.