500 feet beneath the ocean's surface, the U.S. ballistic missile submarine Colorado receives their orders. Through a radio channel designed to be used if the main base has been wiped out, they're told to fire nuclear weapons at Pakistan. Captain Marcus Chaplin (Andre Braugher) demands confirmation of the orders only to be unceremoniously relieved of duty by the White House. XO Sam Kendal (Scott Speedman) suddenly finds himself in charge of the submarine and facing the same difficult decision. When he also refuses to fire without official confirmation of the orders, the Colorado is targeted, fired upon, and hit. With their submarine crippled, and their own nation against them, the crew of the Colorado must survive unprecedented odds and set up a base of operations on a nearby island. Armed with a cache of nuclear missiles and a team of Navy SEAL's, this is their new home, and this is their last resort.