Aboard the luxury British ocean liner Britannic, passengers enjoy a serene voyage when a threatening message disrupts the calm. An anonymous caller claims to have planted seven bombs on the ship and demands a ransom to reveal how to defuse them. The situation garners national attention, prompting the British government to take swift action. Chief bomb disposal expert Lt. Cmdr. Anthony Fallon, along with his team, is urgently dispatched to the ship. The team faces the daunting task of locating and dismantling the bombs while ensuring the safety of everyone aboard. Tension escalates as the clock ticks down, and the team works meticulously to prevent a catastrophe.

Simultaneously, the ship's captain, Alex Brunel, struggles to maintain order and composure among passengers and crew. Authorities on land attempt to trace the caller, leading to a frantic investigation driven by mounting pressure. Relationships among passengers unravel, adding emotional depth to the high-stakes scenario. As danger looms and hope wavers, each character's resilience and resourcefulness are put to the ultimate test. The narrative weaves through moments of heroism, urgency, and suspense, never losing sight of the looming threat that could endanger countless lives.