The film stars Penelope Ann Miller, Tom Sizemore, Linda Hunt, and James Whitmore.

In the film, a detective and a biologist try to defeat a South American lizard-like monster which is on a killing spree in the Field Museum of Natural History in Chicago.

John Whitney, an anthropologist for the Field Museum of Natural History in Chicago, studies a tribe in South America and drinks a soup made by the tribesmen.

Chicago PD homicide detective Lieutenant Vincent D'Agosta and his partner, Sergeant Hollingsworth, investigate the ship and find dozens of bodies and severed heads in the bilge.

Another week later, Margo Green, an evolutionary biologist, arrives at work at the museum and discovers that co-worker Greg Lee is applying for the same research grant she is after he had gotten one for himself already.

Frock and Margo, trapped in the laboratory wing, continue working and discover Ford's killer is after the hormones on the leaves.

During the hysteria, the museum's alarms are tripped and their security system goes haywire, trapping a small group of people inside.

D'Agosta meets Margo and Frock in the lab, where the creature - revealed to be the Kothoga, an enormous chimeric beast - attacks them; they close a steel door to stop it.

Margo theorizes the fungus mutated a smaller creature, and Frock says that without the leaves to eat, the Kothoga instinctively seeks the closest substitute, human hypothalami, until it runs out of targets and dies; he further postulates that the tribe knew of the fungus, and used it on a human or animal to deal with an external threat, then hid until the threat was destroyed and the Kothoga died of "starvation."

Tom, Greg, and benefactors Mr. and Mrs. Blaisedale refuse to go, and CPD officer McNally stays behind to guard them; the Kothoga returns to the main hall and murders them and the S.W.A.T.

As dawn comes, D'Agosta and a team of police break into the lab, see the charred remains of the Kothoga, and rescue Margo from the tank.

The Relic was based on the horror novel by Douglas Preston, an ex-journalist and former public relations director for the American Museum of Natural History in New York City,[5] and Lincoln Child (though it omits their major character, FBI agent Pendergast).

[7] Penelope Ann Miller had not done a horror film prior to The Relic but was drawn to director Peter Hyams' desire to have a strong, smart female lead.

[12] James Berardinelli of ReelViews said that "when all is said and done, this horror/science fiction amalgamation seems like nothing more ambitious than a bad reworking of elements from Aliens, Species, Jaws and Predator.

Peter Stack of the San Francisco Chronicle gave the film a mixed review, stating, "'The Relic' will quickly fade to video, where it might fare well as a bump-in-the-night benefiting from the fast-forward button.

"[17] In a more negative review, Richard Harrington of The Washington Post stated, "It's a familiar story in the horror film business: good novel, terrible adaptation (just ask Stephen King and Clive Barker).

As written by Douglas Preston and Lincoln Child, "The Relic" deserved to be taken off the shelf; as adapted by a quartet of screenwriters and directed by Peter Hyams, it should have been left on one.