Filmed on location in Switzerland, Walt Disney's Third Man on the Mountain was based on Banner in the Sky, a book by James Ramsey Ullman. James MacArthur plays a Swiss youth who vows to be the first to scale a formidable Matterhorn-like mountain called the Citadel. The fact that MacArthur's father was killed attempting a similar climb only strengthens the boy's resolve. Though discouraged by his mother and uncle, MacArthur prepares for his ascent by taking practice climbs with his friends, learning vital lessons about safety and cooperation along the way. Finally, MacArthur begins making his way up the Citadel in the company of four other hardy souls. The title is a giveaway as to who doesn't reach the top of the mountain first; even so, there's a happy, satisfying ending for the so-called "loser." The film's breathtaking full-color shots of the Matterhorn are brilliantly augmented by the matte work of the legendary Peter Ellenshaw. Watch for Helen Hayes, the mother of Third Man on the Mountain star James MacArthur, in an amusing cameo role.
~ Hal Erickson, All Movie Guide