Warning Sign is a 1985 American science fiction-horror film directed by Hal Barwood and starring Sam Waterston, Kathleen Quinlan, Yaphet Kotto, Jeffrey DeMunn, and Richard Dysart.

In a secret military laboratory operating under the guise of a pesticide manufacturer, a sealed tube is broken, starting an outbreak of a virulent bacteria.

Detecting the release of the biological weapon, Joanie Morse, the plant's security officer, activates "Protocol One," a procedure sealing all of the workers inside from the outside world.

Cal Morse, a County Sheriff and Joanie's husband, is advised to retain the help of Dr. Dan Fairchild, a past employee who is a known alcoholic.

Connelly appeases the public with the cover story of a contamination of experimental yeast while a rescue team arrives to administer the antidote to the workers.

Upon the rescue team's death, USACT activates "Protocol Two", leaving all employees to await the deadly effects of the weapon and sanitize the location afterwards.

Joanie retrieves the antidote and flees while Schmidt attacks the P4 workers, breaking Kapoor's neck before being killed by the rest.

Before being incapacitated by his infection, Fairchild enters a recipe for a new antidote based on Joanie's condition into a computer; it contains thorazine to make the patient sleep during their recuperation.

Armed with injection guns, Cal and Fairchild inoculate infected workers while Joanie takes a batch of the new antidote to the building's decontamination system.

Fairchild invites Cal and Joanie back to his home for breakfast - Zucchini pancakes and genetically modified corn on the cob.

[3] Rick Kogan of the Chicago Tribune wrote: "Warning Sign fails to deliver any substantive messages or any genuine thrills.