Trintignant is brilliant, aided by a terrific supporting cast, as a nihilistic but debonair professional thief. The plot is very clever with many surprising twists and turns, and this is combined with a philosophical spirit that transcends description. The film within a film angle has never been handled with more panache. I just saw it this week after not seeing it since the 70's, and the film stands the test of time marvelously -- still as fresh, funny, and involving as when I saw it originally. I recommend this overlooked jewel very strongly.