Teenagers partying in the park are killed by a group of mutated maniacs. Contrary to the title, they do not glow brightly, but the neon refers to their bodily fluids as they glop they leave behind in neon.
Natalie, the lone survivor of the attack, tells the police what happened but they don't believe her. In fact, none of the parents of the missing kids believe her either. Everyone keeps saying it must be a prank. Yeah, what a great joke. Hey gang, let's all disappear and have Natalie tell everyone we were slaughtered. We'll all have a good laugh over that one.
The only person who actually believes Natalie is Paula, a junior high student who is into monster movies. In a disturbing casting move, Paul appears to be close to thirty even though she is playing a kid, which is symbolized by her baseball hat being slightly askew. It's also odd to see a horror movie loving kid to film a vampire movie during the day.
When Natalie won't talk to Paula, she takes it upon herself to go to the murder scene and try to get some footage of the killers.
She tracks the monsters to under the Golden Gate Bridge and using her movie camera, (which would have been an out of the ordinary thing for a kid to have in 1986), she attempts to film them but is seen by the monsters and has to flee. But not before discovering that their Achilles heel is water.
Natalie starts dating delivery boy Steve and the two end up teaming up with Paula as the maniacs keep trying to kill Natalie. Their brilliant idea is to try to dispatch the monsters at the battle of the bands Halloween dance at the high school where Steve is singing his horrible songs.
This goes horribly wrong as everyone is in costume and by the time they see the maniacs, it's too late and there is a panic with everyone forgetting to use their water pistols on the creatures. This leads to the police finally considering what Natalie has to say seriously. I'm not going to say more than that, except that this is one of those movies that has no real resolution and I'm not sure if they just couldn't figure out how to end it, or were preparing the way for a possible sequel.