Television reporter Angela Vidal (Jennifer Carpenter) and her cameraman (Steve Harris) are assigned to spend the night shift with a Los Angeles Fire Station. After a routine 911 call takes them to a small apartment building, they find police officers Wilensky (Columbus Short) and McCreedy (Andrew Fiscella) already on the scene in response to blood curdling screams coming from one of the apartment units. Unbeknownst to them, a woman has contracted a rare strain of rabies. When they try to leave the building with those injured from a wild attack by the infected woman, they find that they've been locked in. Indeed, there are police, SWAT and CDC crews securing the building. But phones, internet, televisions and cell phone access have been cut-off, and officials are not relaying information to those quarantined inside.