Six Navy SEALS, one seriously shot up, speed away from the Pakistani coastline in a pontoon boat. The inflatable craft is lifted out of the sea as the Ohio-class nuclear missile submarine, the U.S.S. Colorado, surfaces beneath it. The SEALS are brought aboard to meet Captain Marcus Chaplin (Andre Braugher) and his Executive Officer (XO) Sam Kendal (Scott Speedman). Lieutenant Grace Shepard (Daisy Betts) takes the Conn as a Pakistani warship bears down on their location. Thankfully, they are not at war.
Master Chief Joseph Prosser (Robert Patrick) warns the captain that their visitors are wound pretty tight. This doesn't stop Sam from asking why the SEALS were attacked. No response. SEAL Officer James King (Daniel Lissing) is privately asked by the warrant officer what happened back there. Again, no response. Moments later, Sam corners Pilar Cortez, one of the nine female sailors aboard the sub, to ask if any male crew member has acted in an offensive manner toward her. It's a weekly thing these two do.
Marcus gazes at a photo of his soldier son, Jeffrey, as Sam enters his quarters. He lets his XO know that he recommend him for desk assignment stateside. Marcus believes it's time for Sam to start a family with his wife, Christine (Jessy Schram). The salutes of respect these two share during a musical celebration as the sub crosses the equator lets us know that the XO ultimately agrees with his captain.
"BATTLE STATIONS!" Marcus barks the command the moment an Emergency Action Message (EAM) comes in. An alarm sounds throughout the Colorado. The message is a missile fire order from Antarctica. The order is authentic and also unusual, as the secondary Antarctic network is only used if the main one has been taken out by a first strike. Marcus and Sam each insert their key into the firing station computer. They have been ordered to launch nuclear missiles on Pakistan.
Sam convinces Marcus to verify that the main network has been destroyed before firing. All indications are that it hasn't. Marcus breaks radio silence by calling National Command in DC. This is much to the chagrin of Master Chief Prosser, who believes they need to follow their authenticated orders. Marcus wants the order to come from someone whose authority he recognizes. The Deputy Secretary of Defense calls back. He relieves Marcus of his command. Sam is now in charge.
Sam orders Grace to insert the captain's firing key into the computer, but does not give the command to turn it. Instead, he asks that the fire order be sent via the regular EAM channel. Click. The line goes dead. SEAL officer James King and the warrant officer storm the Conn demanding to know why the fire order hasn't been followed. They draw guns on the crew. This little brouhaha is interrupted when there's a warning that an inbound cruise missile is headed their way.
KABOOM! A shockwave sends the Colorado sliding along the ocean floor. There's significant damage as water fills the sick bay area. Sam scrambles with the SEALS to save the wounded. More casualties arise as the warrant officer is killed instantly as a blown rivet rockets into his skull. James helps Sam close the infirmary hatch to stop more water from spilling in. The situation aboard the Colorado is dire.
Kylie Sinclair (Autumn Reeser) is a gorgeous, well-educated, charming Washington lobbyist for her family's weapons manufacturing company. She's placed a prototype aboard the Colorado that allows it to hide its magnetic signature. Kylie dismounts her date immediately when she receives a message on her phone that reads "472 Chaplin." She's on the move.
On the island of Sainte Marina, "Mayor" Julian Serrat (Sahr Ngaujah) serves as the unelected ruler of the port city of Soubourg. He has no qualms about entering the NATO Early Warning Station unannounced where Sophie Girard (Camille de Pazzis) is in charge. Her British tech assistant, Nigel, is on the phone trying to get info about the missile they just tracked. Sophie lets him know that it was an American Tomahawk. The crew of the Colorado also learns that they were fired on by the U.S.S. Illinois. In other words, they were attacked by their own people.
Sam lets Marcus know that he needs his help. His plea seems to fall on deaf ears. The Colorado is able to lift itself off the ocean floor and returns to operational status. Sam lets the crew know that the officers will eventually explain their actions to the proper authorities. In the meantime, everyone is to do their job. This includes Marcus, who reassumes command of the sub. He orders the crew to head for a safe harbor.
Back in the States, Sam's wife, Christine, believes her husband is dead. News reports state that a Pakistani warship fired at and sank the Colorado. Kylie Sinclair confronts Grace's father, Admiral Arthur Shepard, at the Pentagon regarding the lie he's telling about the attack. She believes the U.S. sank its own boat because the text she received signified the nuclear sub had a rogue captain. The admiral goes way back with Marcus. It's clear that he has no idea what Kylie is talking about.
Aboard the Colorado, Grace knows that she has yet to earn the respect of many members of the crew, not to mention Master Chief Prosser. She also knows that she would have turned that missile launch key had Sam asked her to do so. She's grateful to him for taking a stand against annihilating millions of people. This appears to be exactly what's happening above the surface of the water. Sophie and Nigel track two nuclear missiles that detonate inside Pakistan.
Marcus orders the Colorado to surface in the Sainte Marina Harbor. The islanders are in awe of the massive craft that has just pulled up to their front door. James meets the owner of a local bar, Tani Tumrenjak (Dichen Lachman). He asks her to store his dead friend's body until he can get him home. James then engages in an intense, territorial-themed conversation with Julian. He assures the "mayor" that his days of running things on the island are over.
The crew of the Colorado takes control of the NATO station. Marcus calls Admiral Shepard, who is relieved to learn that Grace is alive. As the two old friends try to make sense out of what has happened, soldiers enter the office. They hang up the admiral's phone and escort him away. Sam calls Christine to let her know that he's safe. Their conversation is also cut short as the power in the NATO station is disabled. This is done by members of the Colorado crew.
Sam draws his gun on the crew member who cut the power in order to strategize with Command. Another crew member, Stern, draws his firearm on Sam. It's a standoff. Some members of the Colorado believe the captain should have followed his orders. Stern is willing to kill Sam to prove this. BANG! Stern slumps to ground having been shot from behind by Grace.
Two bombers are incoming toward the Colorado. All members of the crew reassemble on the sub. Only Cortez and Seaman Josh Brannan are MIA. Marcus knows they need to change the game. He fires a missile that's headed toward DC. He lets Washington know that the missile will detonate if the bombers headed their way aren't turned around pronto. It's an intense game of chicken. Marcus lets his crew know they will not survive the attack. He prepares to destruct his missile when the bombers suddenly turn back.
Marcus tells Washington they were too late. Sam is in disbelief. The captain assures him that this move is in their best interest. The missile detonates in the Atlantic 200 miles east of DC. No one is hurt, but a message has been sent. Sam believes that everything they've done was to clear their names so they can ultimately go home. Marcus believes that this island may be their home now.
In random news, Cortez and Brannan have been captured and are being held hostage by Julian. James believes he's the one who caused all that's happening. We're not exactly sure why. Grace places Prosser under arrest, as he blatantly challenges her authority. He surely won't be the only one, as loyalties amongst the crew of the Colorado appear to be divided. Grace also overhears one of the wounded SEALS say they killed the wrong people. Back in the States, it's clear that Admiral Shepard wants Kylie's help to find some answers.
Marcus relays a video communication to all governments, the U.S. included, laying out the details of how they were left for dead by their own country. He declares a 200-mile no man's land around the island. If this perimeter is breached, he will not hesitate to use their 17 remaining nuclear missiles to unleash some fiery hell. The world has been warned.