For the NASA-funded research team stationed at the most desolate reaches of Antarctica, it's another routine day--until the communications satellite picks up a mysterious signal coming from a strange object lodged several meters beneath the ice. Suspecting it may not be from Earth, the lead scientist immediately places a call to Julian Rome (James Spader), an old friend formerly employed as a cryptologist for the U.S. government's SETI (Search for Extra-terrestrial Intelligence) programme. Catching the next flight to the South Pole, this former "alien hunter" is soon led to the unidentified object which is still encased in a large block of ice. After constructing a makeshift decoder, Rome quickly cracks the complex mathematical code, only to discover the message is an alien warning. Now it's a terrifying race against time to prevent the total annihilation of the planet.