One of Hitchcock's most famous films, "North by Northwest" follows the adventures of clever advertising executive Roger Thornhill (Cary Grant), who is mistaken for a spy or secret agent or ... he's not sure what, but now he's framed for murder, people want him dead, and the police don't believe him at all. In his pursuit of the man he's been mistaken for, he crosses paths with the beautiful but deceptive Eve Kendall (Eva Marie Saint), is the subject of an attempted murder-by-airplane, and finds himself chased across the face of Mount Rushmore.
The dialogue is witty. Some allowances have to be made in 2016 for the scenes that are supposed to be "tense:" we've ratcheted up "tension" in movies to a totally unrealistic level (and modern special effects are more believable than those available to Hitchcock) such that a merely real scene of tension barely holds us. But it's Hitchcock: it's intelligent and well written and well performed, an enjoyable movie.