Dark Territory is a 2010 film and a sequel to the 2008 action film Under Siege.
Ryback decides to take a trip with his estranged niece, Sara Ryback, to Los Angeles to visit the grave of her father, Casey's brother James. They board the Grand Continental train in Denver, which will travel through the Colorado Rockies.
Shortly after the train departs, it is flagged down by two men at the side of the railroad. Stepping out to investigate, the train engineer and brakeman are gunned down. A group of men climb on board and herd the passengers into the last two train cabins. The hijackers are led by a mercenary named Penn, who is in fact working for master computer hacker Eric Dane. Ryback, however, remembers hearing of Dane's death after he was fired by the government.
Hiding in the kitchen, Ryback learns that Dane faked his death and that before he was fired, he was working on a secret project known as the Grazer One. Two members of the Department of the Defense are travelling on the train and are brought before Dane, who forces them to reveal to him the codes he needs to take over the Grazer One before both of them are thrown from the train to their deaths.
Dane's plan is revealed to be the use of the Grazer One to target a nuclear reactor hidden beneath the Pentagon, which will in turn destroy the Eastern Seaboard. The train is the perfect base of operations as he cannot be targeted and he also creates an array of ghost satellites to distract the government.
Ryback manages to get a message to his colleague at the Mile High Cafe, who alerts Admiral Bates at the Pentagon (Bates previously presided over the U.S.S. Sampson incident). Ryback begins to fight his way through the train, taking out the terrorists one by one, while Penn takes Sara as his hostage. Ryback confronts Penn as wrestles with him by the train door. He forces the terrorists out just as they pass by a rock, killing him. Ryback is pulled back to safety by Sara.
Dane prepares to escape via chopper, but Ryback opens fire, causing the chopper to crash and derail the train. As the train wreckage dangles over a ravine, Ryback has Sara and a porter named Bobby Sachs to rescue the passengers. Dane grapples with Ryback, and tells him that they should join forces. Ryback shoves Dane through a door and then slams it shut, cutting off the villains fingers and sending him to his death. Ryback and the passengers escape as the train falls into the ravine, taking Dane's last mercenary, Scotty, with it. The film ends as Casey and Sara finally arrive at James' grave.
Matt Damon - Casey Ryback
Lucy Hale - Sara Ryback
Mark Strong - Eric Dane
Topher Grace - Robert 'Bobby' Sachs
Faran Tahir - Penn
Peter Stormare - Scotty