Carver Wells finds himself trapped and fighting for his life after an ER patient unleashes a deadly contagion that throws a hospital into a quarantined lockdown.

SYNOPSIS:

Carver Wells arrives at Ventura County Medical Center during evening visiting hours to spend time with his terminally ill brother.

During Carver's final moments with William, an ambulance arrives at VCMC's Emergency Room transporting an unknown male exhibiting a variety of symptoms, including excruciating pain and a strong tendency to violence.

The latter becomes evident when the agitated man on the gurney inflicts a severe bite on Officer Bailey's hand. Bailey's one of two police officers assisting the EMTs in getting their patient into the ER.

Once the man on the gurney is transferred to a bed in the ER, he is put under restraints to protect anyone else from being harmed. As doctors and nurses on duty rush to treat their new arrival, his condition worsens with thick, ugly scabs and swollen blisters sweeping across his body from head to toe.

When Officer Bailey develops the same blisters and scabs, a doctor orders a nurse to call 911.

As the ER medical team copes with two infected individuals, the swollen blisters on the first patient's body explosively rupture, spraying their poisonous contents on everyone nearby.

The unknown contagion spreads like wildfire, infecting doctors, nurses, Officer Bailey's partner, and the two EMTs responsible for bringing Patient Zero to the hospital in the first place.

Meanwhile, in his brother's fourth-floor room, Carver's visit ends when sirens from below entice him to look out his brother's window to see what's going on.

As Carver watches, local police officers appear to gun down two men attempting to exit the hospital. One of the victims, Carver is sure, is a doctor.

Carver goes to the floor's nursing station and asks Nurse Jenny to call the ER to see if they're experiencing some kind of problem. When Jenny can't get through to the ER, Carver has her try calling hospital Security with the same results.

But it gets worse as they soon discover that all means of communicating with the outside world have been cut off.

By now, the hospital is surrounded by police and SWAT teams. Nobody gets in or out.

With the contagion rapidly spreading throughout VCMC, Carter teams up with night custodian Pablo Rivera to use every resource available to enable them to survive long enough to be rescued.

The likelihood of that happening, though, quickly fades when they witness a crazed mob of infected individuals from outside VCMC attack the authorities circling the hospital, the assault forcing several SWAT team members to seek dubious refuge inside the already dangerous hospital.

Grossly outnumbered by their infected foes on every floor, Carver, Pablo, and Jenny must fight for their lives to the bitter end.