The film begins with an enigmatic figure sketching intricate diagrams to the haunting melody of Silent Night. As he dons his parka, he departs into the cold night. During a festive office Christmas party, David Hargrove extends an offer to drive his colleague Emily Brandt home. Although reluctant, he allows his carefree friend Corey Thompson to tag along. On their way, Corey insists they stop at a 24-hour ATM kiosk to withdraw some cash. After a brief moment, Emily joins them, revealing that the car's lock clicker isn't functioning.
Just as they plan to leave, they notice a sinister hooded figure, ominously referred to as THE MAN, lurking outside. While Corey suggests retreating to the car, both David and Emily hesitate, suspecting he might be a robber. Suddenly, a passerby named Robert appears, walking his dog, but the calm is shattered when THE MAN brutally attacks Robert without hesitation. Terrified, the trio attempts to alert the authorities; however, Corey has misplaced his phone from the party, David's is dead, and Emily's lies unreachable in her purse within the car. Their attempts to create a ruckus at the ATM yield no results as panic sets in.
When THE MAN notices their frantic movements, he approaches their car, rummaging through the trunk and extracting various items, including a tire iron and a toolbox, before cutting off the illumination and heat in the ATM kiosk. Desperate, David decides to confront THE MAN, offering him cash and valuables in exchange for their safety. But as he tries to make a run for Emily's phone to call 911, THE MAN strikes with brute force, pulling him outside while Corey distracts the assailant.
In a moment of grim resourcefulness, Emily uses her lipstick to scrawl "HELP" on the ATM window. Their hope dwindles as time drags on, especially after a Security Guard arrives only to meet a tragic fate at the hands of THE MAN. As Emily begins to succumb to the biting cold, they find themselves in an increasingly hopeless situation, with dangerous encounters continuing to unfold.
Hours later, they mistakenly kill an unsuspecting man in a similar coat, later identified as Harold, but they find that their real adversary remains at large. As the temperature plummets, Corey, injured and angry, attempts to flee but is ultimately caught and stabbed by THE MAN. David and Emily manage to bring him back to safety, but their victories are fleeting. Their desperate attempts to signal for help and break free from their icy entrapment fail miserably.
With the ATM filling with freezing water, Corey's condition deteriorates, and soon he succumbs to his injuries. A flicker of hope raises when David discovers a lighter and sets a fire to alert rescuers. However, their escape plan takes a tragic turn when Emily suffers a fatal accident.
In a climactic twist, David manages to concoct a Molotov cocktail, only to mistakenly target a deceased Security Guard. As the police arrive, they apprehend David, finding evidence that suggests he, Corey, and Emily were the perpetrators of an ATM heist, while THE MAN remains undiscovered in the footage—a ghost in the shadows.
In a chilling epilogue, the nefarious hooded figure returns to his lair, revealing meticulous plans of further ATM attacks, implying that he has long been orchestrating and evading justice while innocent lives fall victim to his insidious schemes. This horrifying insinuation leaves the audience questioning the depths of his malicious intentions as David becomes the scapegoat for the monstrous acts committed that harrowing night.
