Deep in the Alaskan wilderness, a team of scientists at an isolated weather station begins receiving an unexplainable radio frequency. It comes at regular intervals—every 47 minutes—always the same four tones. No one knows where it originates, and it’s not on any known spectrum.

Dr. Elaine Park, a communications expert, starts decoding the signal, convinced it holds a message. As the signal grows louder and more insistent, strange phenomena begin: birds fly into windows, equipment malfunctions, and team members report hallucinations.

Then one night, a power outage plunges the station into darkness. Park discovers that the tones are not man-made but a language. They are coordinates—marking the station itself.

Realizing the signal is not a call for help, but a summons, she races to shut down all broadcasting. But it’s too late. The last transmission is answered by something ancient, buried in the ice, now awakened and walking toward them.