After an altercation between Alex, the president's son, and Britain's Prince Henry at a royal event becomes tabloid fodder, their long-running feud now threatens to drive a wedge in U.S./British relations. When the rivals are forced into a staged truce, their icy relationship begins to thaw and the friction between them sparks something deeper than they ever expected.

When photographers Erin and Patrick are brought aboard the ship with their young son Lukas, they unleash a series of events that entwines their family with the ship’s dark past. As the terror unfolds around them they begin to realise there is more to this sumptuous ocean liner than meets the eye: its remarkable legacy masking violent secrets.