This is an interesting slasher, from 1980, starring Jamie Lee Curtis. Set on a train, it's like Serial Killer on the Orient Express. (Or Halloween meets The Silver Streak, according to the lore on IMDB's trivia page.)
You've got above-average cinematography and production values, and the setting feels authentic, being filmed on an actual train. The tension doesn't really kick in until the final third, but it works pretty well once it revs up. There are some pretty good jumps, even for the hardened, modern-day horror viewer.
Until then, we observe a train load of semi-unlikable med students partying, and get to know their characters as they drink, fool around, argue and dance to disco music. This is handled capably, but can drag on at times. The acting is natural enough that it provides an always-interesting time machine to observe the behaviour of 20-somethings in 1980.
Hart Bochner, who played the cocaine-snorting executive in Die Hard, gets to play another asshole in this film. Actually, a number of people get to play assholes. So for the first few killings, they almost seem justifiable, in that horror movie way.
Directed by Canadian Roger Spottiswoode, who's gone on to do a wild range of movies, from Under Fire to Stop or My Mom Will Shoot to Shake Hands with the Devil!