So the plot's pretty simple. The United States secretly built a ship capable of creating wormholes. You know, because that's obviously the type of thing a single government could produce and keep secret, especially when its track record for coverups is a joke. Furthermore, if you want to keep a ship's jump-drive a secret, it's probably not a good idea to publicly name it Event Horizon (I'm reminded how the government in Deep Impact covered up the impending comet strike with the code name E.L.E.: Extinction Level Event). Instead of testing the ship's ability to jump from point A to B with probes and robots, they put a human crew on it for its maiden voyage. Well, surprise: the ship disappeared and was never heard of again. That is until seven years later when it shows up in Neptune's orbit.
A rescue ship is sent to investigate the Event Horizon. Sam Neill is the scientist who created the ship, Laurence Fishburne is the captain, and Kathleen Quinlan looks surprisingly good in a tank top. This is a really good cast wasted by a director who has all the emotional complexity of a twelve year old boy. Anyway, spooky shit begins to happen because fuck science and humanity's drive to explore, right? Maybe that's why I hate movies like this: it's like Hollywood wants us to live on our little planet forever so they continually punish any character for taking part in the final frontier.
it seems impossible for a movie to make this stuff so boring
It's fair to compare Event Horizon to Alien, even though that's like comparing restroom graffiti to Picasso, because it so desperately wants to be Alien. While you don't have cats falling out of the ceiling, the jump-scares in Event Horizon are the equivalent of awkward one-liners shoehorned into a bad action movie. I actually like jump-scares when they work (Drag Me to Hell was hilariously brilliant at it), but here they don't. Not even once. But it's a good thing they're there because I found my eyes drifting to places other than the screen and the screeching violins reminded me to watch the movie.
Other than all that, Event Horizon isn't without its merits. I like the way it looks even though there's no logical reason for the maintenance tunnels to be an eerie color or there to be lights on the wormhole generator, and so on. The CGI in this movie is downright horrible, but the other effects are pretty solid. The film's biggest problem is that its weird shit happens prematurely. There isn't any building of tension and therefor the scare tactics fall embarrassingly flat. It would also help if we gave a shit about any of these characters, but we don't because they're just not real enough.
A little late in the picture it's made clear that Fishburne's character had a traumatic life experience. We sigh because we know they'll try to resolve this inner conflict by the third act, which they do in the span of about ten seconds. It's so brief, in fact, you wonder what was the point of introducing it at all. Wikipedia says the movie underwent an uncredited rewrite and I'd bet money it was a much better movie before that happened.