The plot, like so many of them, takes place in Los Angeles. Tucker (played by Bill Paxton) and Terri Flynn (played by Lindsay Frost) are pair of tough LAPD detectives that are investigating the murder of a small boy. The killer is emotionally disturbed scientist, but, before they can find out any motives for the killing, the suspect and all the evidence is taken over by Department of Historical Research, led by menacing Villano (played by John Hurt). Of course, Tucker and Flynn decide to investigate further, and they find a lot of violent incidents in the city - incidents involving some malevolent alien force, capable of taking over human bodies. But, before they anything about it, they must take care of Villano and his henchmen, who would stop at nothing to suppress the truth.

The concept of this film, although it resembles X-FILES (that had the first season in the same year), is actually very unoriginal - some mean alien coming to Los Angeles and being unstoppable, until few dedicates members of LAPD take care of him (like in I COME IN PEACE or HIDDEN). The screenplay by Steven Lister is awful - it simply doesn't connect the dots between obligatory action scenes, the characters are unappealing and wooden, and the plot contains wholes with the size of Nebraska. Of course, there are some huge implausibilities (like organisation called Department of Historical Research taking over murder suspects from LAPD) that look like an insult to viewer's intelligence. If Lister and director Eyres made those mistakes deliberately, trying to turn this film into self-parody, they failed. The film looks dead serious. Some actors, like Louis Gossett Jr. and John Hurt, are doing their work very well, but they can't breathe life into bad and stereotypical roles. Paxton and Frost are, on the other hand, totally deprived of any chemistry between the characters they play, either romantic or classic "buddy buddy" model. Some action scenes look interesting, but a lot of pyrotechnics and special effects won't change the verdict on this film - MONOLITH is failed film that should be avoided.