Warning Sign

A sealed tube breaks in a secret military laboratory operating under the guise of a pesticide plant, starting an outbreak of virulent bacteria. Joanie Morse activates Protocol One to seal the workers inside and prevent escape. The facility shifts from routine operation to urgent containment as the threat surfaces.

Joanie confirms the lockdown and workers are sealed off from the outside world. Tom Schmidt and Bob restart the plant's pump, misattributing the incident to a malfunction. Their actions undermine containment as contaminated air begins circulating again.

Cal Morse, a county sheriff and Joanie's husband, is advised to enlist Dr. Dan Fairchild, a former employee who developed an antidote concept. Vic Flint joins the response team to assist. The group becomes the core of the front-line effort.

USACT arrives at the facility and establishes quarantine procedures. Major Connelly publicly references a cover story about contaminated yeast to explain the situation. A rescue team is dispatched to administer the antidote to workers.

As containment is breached, workers sanitize the lab, destroy animals, and inoculate themselves with the antidote. The rescue team also uses the antidote as the outbreak expands its reach. The air grows thick with fear and urgency.

A power outage cripples systems and an air lock is smashed from inside. The USACT team locates Dr. Nielsen and his people incapacitated on the lab floor, but their bodies disappear shortly after. Kapoor sabotages a power box, worsening the containment.

A subset of workers believes they are unaffected and attempts to leave quarantine. Joanie had destroyed the code page but recalls it; Tippett tortures her for it. The code is revealed to be invalid once USACT taps into the system.

The rescue team orders the group to remain under quarantine, but Tippett refuses and is killed. The others are placed in a room to await inoculation as the team moves to further actions.

Fairchild directs the team through an unoccupied service conduit toward the P4 lab. They encounter Nielsen and retreat when something feels wrong; the group is ambushed by P4 workers, and one attacker is killed by Kapoor.

USACT activates Protocol Two and leaves the workers to confront the contagion's deadly effects. Cal presses Fairchild to join in retrieving the antidote, setting the plan in motion.

Cal encounters infected Bob, who attacks; Cal is forced to shoot Bob to protect the team. The confrontation underscores the severity of the outbreak.

Joanie joins Schmidt on a mission to the P4 lab to retrieve the antidote. They encounter Nielsen and Kapoor and manage to escape the attack, continuing toward the antidote.

In the P4 lab, Schmidt succumbs to the infection while the P4 workers close in. Joanie retrieves the antidote and flees; Schmidt attacks the workers, breaking Kapoor's neck before being killed.

Joanie learns she is pregnant, with blood rich in estrogen, progesterone, and antibodies. Fairchild develops a new antidote recipe that includes thorazine to sedate patients, and it works when tested on Fairchild.

Cal and Fairchild inoculate infected workers with the new antidote using injection guns. Joanie uses the building's decontamination system to disseminate the antidote and end the threat. Nielsen commits suicide as his plan collapses, and USACT evacuates the victims and seals the facility.