In comparison with such serious-minded psychological thrillers as Vertigo and Psycho, Alfred Hitchcock’s 1959 espionage flick North by Northwest could almost be considered “light fare” for the Master of Suspense: Surprising wit, flirtatious dialogue, and atmospheric action sequences make the film so immediately entertaining that, if not for Hitchcock’s subtly guiding hand, you might miss the depth beneath the characters’ cool exteriors. Cary Grant stars as smug advertising executive Roger Thornhill, who, after being accidentally mistaken for a government agent by a group of enemy spies, sets out to clear his name. Stumbling his way through the world of international intrigue, Thornhill suffers a series of cross-country misadventures, culminating in a climactic chase across the top of Mount Rushmore. Beautifully shot, perfectly acted, and seething with tension, Hitchcock’s depiction of the loss of identity in Cold War America easily stands among his best efforts. It shows at 8:15 p.m. at the Comcast Outdoor Film Festival, 10701 Rockville Pike, Rockville. Free. (301) 816-6958. (Matthew Borlik)