Ali Gorski, a former Marine struggling with PTSD after a traumatic mission, takes a job as a doorman at a luxurious New York City high-rise. The building is mostly empty due to ongoing renovations, and her primary responsibility is to look after the few remaining residents, including a family she becomes protective of. As Ali tries to find peace in her new mundane role, she unintentionally stumbles upon a sophisticated art heist plot orchestrated by a ruthless gang led by Victor Dubois.

Realizing the gravity of the situation, Ali must quickly revert to her combat skills to protect the innocent residents and thwart the criminals' plans. Confronted with both physical and psychological challenges, she battles the gang members in a series of intense confrontations throughout the building. As Ali races against time, her journey becomes one of redemption and self-discovery. The stakes escalate, culminating in a high-stakes showdown where Ali must rely on her training and resourcefulness to survive and save those she has come to care about.