When an unidentified object is shot down over the waters of the Pacific Northwest, an excavation team is sent in to retrieve it. Moments later, a dark cloud spreads through the water and empty wetsuits rise up, floating ominously on the surface-leaving no trace of the people behind. As Seattle officials inspect the debris, the sky grows turbulent, seemingly instigated by the smoke coming off the wreckage. Major Emma Peterson is handed the task of identifying the threat and securing the city, while her fiancé, scientist Tom Reynolds, keeps an eye on their two teenage children. However, the scientist in him is unable to ignore the strange occurrences taking place around him and he sends the teens home, unaware that he is putting them directly into the path of danger. Now the family must find each other in the midst of the chaos and work together to put a stop to the storm before it spreads beyond their control and annihilates the planet!