Did that suck.
I've heard that this was on ok slasher. But it was not. It is a poor film all over the place, from script to direction to performances, it's a real slog requiring actual willpower to make it to the inevitable reveal-scene at the end.
Virginia is sort of the sensitive one out of a group of rich prep-school kids and there's apparently some history/trauma involving her mother or something around that that will eventually sort of matter to the plot, which makes little sense anyway. The kids, played by actors almost uniformly in their early to mid 30s, start getting murdered by a mysterious, black-gloved killer that they seem to know and trust. All of them are complete one-dimensional assholes anyway and it's impossible to care about any of them, especially as most of them behave really inconsistently thoughout making it hard to even have a sense of what they are supposed to be like. One "character" in particular, Rudi, was as baffling to me as any I've seen in a movie. Is he the testosterone fueled jerk who wants to fight? Or is he the her-athlete? The romantic lead? The weirdo with a penchant for old horror movies and a truly sick sense of humor? Well, over the course of a little over an hour, he is all of these. Because the script is garbage and no one here cares except maybe Melissa Sue Anderson who is trying to establish a film career but lacks the talent to do so. One wonders after watching this how she got work in the first place. And of course, you have Glenn Ford, the legendary Glenn Ford, slumming it here for some reason (money problems?) in a role that also makes more or less no sense as Virginia's experimental psychiatrist.
Anyway, kills occur, because Friday the 13th made money, and it ostensibly builds to a climactic scene with a reveal, as these things must. Of course, the reveal is utterly unearned, like as much so as any thriller you'll ever see, and is also completely and utterly implausible, even for this genre, so if you slogged it out this long just for this moment - which I had - you're going to be pretty disappointed that you spent an hour and forty-five minutes of a reasonably viable Saturday on this.
It is worth mentioning that the director was actually a well-known Hollywood veteran who had actually been nominated for many awards including Best Director because the film seems so amateurish so often. It's like he doesn't know what to do with the camera in this genre so he does like everything with it. Fucking thing never stops moving. Drove me crazy. I wanted to punch him in the nuts.
You can really see the influence the Italian "Giallo" genre had on American "Slashers" during this time, there are so many movies with anonymous killers with some reveal at the end, but unfortunately no one involved with this film had any idea what to do with that influence.
Anyway, this film is poor, at best and is for completionists only.