In the midst of a global crisis, with Russian rebels threatening nuclear war, the USS Alabama, an American ballistic missile submarine, is deployed under the command of the seasoned Captain Frank Ramsey and his new executive officer, Lieutenant Commander Ron Hunter. As they head into potentially hostile waters, the differing philosophies and temperaments of Ramsey, a warrior of the old guard who believes in the unquestioned authority of a commanding officer, and Hunter, a proponent of a more cautious and analytical approach to warfare, set the stage for conflict. The tension aboard the submarine is palpable, with the crew split between loyalty to their commanding officer and the more measured approach advocated by Hunter.

The situation escalates when the submarine receives a partial message indicating an order to launch nuclear missiles, but before it can be confirmed, communication with the outside world is lost. The clash between Ramsey and Hunter reaches a boiling point over the interpretation of their orders without full information. Hunter argues for caution and the need to re-establish contact to confirm the order, while Ramsey is determined to proceed with the launch, believing it to be their duty. This standoff forces the crew to choose sides, leading to a mutinous split that threatens not only the lives on board but the very outcome of the potential nuclear conflict.