Years after an alien invasion nearly extinguished the human race, three soldiers who survived on a secret moon base are sent to Earth to liberate the survivors from the Sentinel and its army and reclaim Earth at any cost.
The Sentinel is a 2006 American political action thriller film directed by Clark Johnson about a veteran United States Secret Service special agent who is suspected of treason after an attempted assassination of the president reveals that someone within the Service is supplying information to the assassins.