Seal Team Commander Casey Ryback has retired from the Navy since the conclusion of the events in the first movie, and is now a chef at the Mile High Cafe in Denver, Colorado. Ryback is taking his niece Sarah Ryback on vacation, to reconnect and commiserate with her after the death of her parents. They board a train traveling westbound through the Rocky Mountains from Denver to LA. With the help of gun-for-hire Marcus Penn a couple dozen of his mercenaries, ex-CIA brain (and mentally unstable) Travis Dane commandeers the train, takes the passengers and crew hostage, and sets up a mobile control center. He hacks into the CIA database and gains control of a Top-Secret defense satellite he designed during his Agency days that has just been deployed. Funded by various foreign interests, he stands to make 1 billion dollars for using the space weapon to blow up the Eastern seaboard by targeting a nuclear reactor housed beneath the Pentagon. Dane taunts the Joint Chiefs in the Pentagon Situation Room by using it to blow up a Chinese chemical weapons plant and the two stealth planes sent to intercept him, secure in the knowledge that he cannot be stopped because his location can't be traced as long as the train keeps moving. Ryback, aided by young porter Bobby Zachs, is the only ones who can take out the bad guys, rescue the hostages, and prevent the destruction of the eastern seaboard before Dane can realize his dastardly plans.