Un rebus per l'assassino

This is a perfect example of mature entertainment for its day, made in the deep dark days of the mid 1970s when the F word was rarely heard in cinema not shown in Times Square. Saw this one in the drive-in; yes the drive-in when I was a wee lad with my folks. I don't understand why it isn't better known, but most people I'm sure have never heard of it. It's a good one. Macabre, clever murder mystery with a cast you can sink your teeth into. The clothes, lingo and attitudes are so pathetically 70s; I sometimes find it hard to believe I'm actually this old when I watch something like this. Most of the action takes place on a yacht anchored off of the Italian Riviera, and to me it has always had twisted adult Gilligan's Island feel to it all. The scenes in the monastery are good old fashioned creepy. Find me a director who can do any of this now, without showing bare tetons or dismembered alien corpses, and I'll eat my bellbottoms.