“游牧者一号”是美国国防部开发的配备有超级粒子束武器的同步卫星,他具有高倍的望远镜,并可精确打击地面上任一目标。然而掌握卫星密码的两名技术人员却被疯狂的科学家查维斯·丹(Eric Bogosian 饰)和特种部队上校马库斯·潘(Everett McGill 饰)率领的恐怖团伙所虏获,“游牧者一号”也毫无悬念地被这群家伙所劫持。国防部虽然紧急应对,却无法与狡猾的恐怖分子抗衡,只能眼睁睁地看着华盛顿成为“游牧者一号”将要袭击的目标。 与此同时,前海军特种部队成员西斯·里贝克(史蒂文·西格 Steven Seagal 饰)正与侄女莎拉(Katherine Heigl 饰)搭乘这趟列车旅行。在危急时刻,西斯挺身而出,独自与恐怖分子展开正邪对抗……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 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, his location can't be fixed. 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 realise his dastardly plans!