Lt. Alex Hopper, played by Taylor Kitsch, is a reckless and irresponsible naval officer who, after a run-in with the law, is forced into enlisting in the United States Navy by his older brother, Stone Hopper, who is also a senior officer in the Navy. After a few years of struggling to find meaning in his life, Alex is finally given an opportunity to prove himself when a fleet of alien ships arrives on Earth in response to a radio signal that was sent out by NASA.
The aliens, who are referred to as "The Regents", are a technologically advanced race of beings whose motive for coming to Earth is initially unclear. However, it soon becomes apparent that they are here to steal a valuable resource that the Earth possesses, which they need to power their ships and ensure their survival.
In the ensuing battle, which takes place both on the open seas and on the Hawaiian islands, Alex and his crew work tirelessly alongside an international naval coalition to both fight off the alien threat and prevent them from getting their hands on the precious resource. The film is filled with explosive action sequences, as well as humor and heart, as Alex strives to be the hero that his family and loved ones believe he has the potential to be.