A Soviet submarine captain with a troubled past is tasked with a covert mission during the Cold War. As he embarks on this mission, he is haunted by memories and pressured by tensions within the crew. Amid the secrecy, a KGB group on board complicates matters, seeking to test a new device with potentially disastrous consequences. The captain struggles with his inner demons and the strained relationships among his men, trying to maintain control and focus on the mission.

Simultaneously, loyalties are tested as hidden agendas emerge and the true scope of the mission becomes clearer. The tension rises as conflicting interests threaten to unravel the already fragile situation on the submarine. As events escalate, the captain faces critical decisions that could determine the fate of not only his crew but potentially the wider geopolitical landscape. Everyone aboard must navigate a labyrinth of deception and duty as they move ever closer to an uncertain and perilous conclusion.