The chemistry between Forsythe and Margaret is great because they're such opposites. He's super straight laced, and she's wild. Unfortunately her acting isn't consistent. It's notable for a crazy scene at the 1hr 17min mark. There's a fight with the main 4 characters sped up that is fascinating to watch over and over again. It was probably done so you won't focus too much on Forsythe's stuntman. Crazy man!
Ann-Margret's over the top energy and John Forsythe's stodgy befuddlement play an excellent counterpoint in this extraordinary campy pulp drama. For all its B-movie bravado, this is really some sharp filmmaking from writer-director Douglas Heyes, with some expertly-crafted suspense, great moody black and white photography, and a simmering jazz score. A strange, sexy cult masterpiece.