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 defence 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 ...

1950's Los Angeles is the seedy backdrop for this intricate noir-ish tale of police corruption and Hollywood sleaze. Three very different cops are all after the truth, each in their own style: Ed Exley, the golden boy of the police force, willing to do almost anything to get ahead, except sell out; Bud White, ready to break the rules to seek justice, but barely able to keep his raging violence under control; and Jack Vincennes, always looking for celebrity and a quick buck until his conscience drives him to join Exley and White down the one-way path to find the truth behind the dark world of L.A. crime.