A sinister black freighter moves stealthily through the night, appearing utterly uninhabited. As it draws near to a cruise ship, frantic voices echo, demanding action in German: "Battle Stations! Enemy in sight!" To the horror of everyone on board, the ship’s controls spin wildly on their own.
On the cruise ship, Captain Ashland, portrayed by George Kennedy, is on his last voyage. His successor, Captain Trevor Marshall, played by Richard Crenna, has brought his family along for this journey. Suddenly, the ominous freighter blares its horn, a foreboding signal of impending doom. Despite Ashland’s desperate attempts to avert disaster, the freighter barrels into them, resulting in catastrophic damage and the sinking of the cruise ship.
The following morning unveils a bleak reality as a few survivors cling to life on a sizable piece of wreckage. Among them are Marshall, his wife Margaret, played by Sally Ann Howes, their children Robin and Ben, a young officer named Nick, portrayed by Nick Mancuso, and his love interest Lori, acted by Victoria Burgoyne. They are also joined by the ship’s comedian Jackie, played by Saul Rubinek, and a passenger named Mrs. Morgan, portrayed by Kate Reid. The mangled forms of their lives float aimlessly in the water, grappling with the trauma of their recent shipwreck as Ashland is rescued from the brink of unconsciousness.
As fate would have it, they drift into the path of the ominous black freighter. Oblivious to its dark history, they find a way on board, only to witness Jackie’s futile attempts at humor being cut short when a cable seizes him by the ankle, lifting him into the depths of the ocean, casting him into an eternal void.
In the eerie corridors of the ghostly ship, the survivors are met with bizarre occurrences: doors creak open and shut, lights flicker, and unsettling apparitions loom. A dizzying experience awaits them as a disoriented Ashland hears a ghostly whisper in German, beckoning him: > "This ship has been waiting for you... It is your new ship.... Your chance has come!" His mind clouded by this supernatural influence, the survivors soon find themselves in a dusty bunk room surrounded by a haunting aura.
Exploring the ship reveals an unsettling truth—this vessel, once a Nazi prison ship, holds the tortured souls of its former crew and captives. The atmosphere becomes increasingly menacing when a film projector and record player seemingly operate on their own, raising the survivors' suspicions. The chilling moment escalates when Mrs. Morgan, in a dreadful twist, suffers a grotesque transformation after consuming candy from the ship's eerie cupboards.
Driven by nefarious forces, Ashland dons a German naval uniform, claiming command over the haunted vessel. Meanwhile, dreadful realizations dawn on Marshall and Nick as they discover the ship's ghastly past. Attempting to escape, they are thwarted when the lifeboats mysteriously descend into the ocean without control, sealing their fate along with the rampaging specters.
As the tension rises, the survivors’ hope dwindles. Lori experiences sheer horror as the water in her shower turns to the color of blood, leading to her tragic ejection from the ship by Ashland, further showcasing his descent into madness. As chaos mounts, Nick struggles against Ashland, but tragically falls prey to the ship's deadly traps.
Amid the turmoil, Marshall discovers a life raft stored within a freezer, packed with the remnants of the ship's prior victims. With desperate urgency, he fights against the encroaching darkness. However, the horror escalates again as Ashland captures Margaret, now a twisted shell of the captain he used to be. A sequence of events arises wherein Ashland's gun jams as he attempts to eliminate the Marshall family.
Ultimately, in a move of violent destruction, Ashland meets his own grisly fate, fatally crushed by the ship’s mechanisms, his soul forever entwined with the vessel's cold heart. As the haunting cries of the ship's past victims echo through its empty halls, the Marshalls manage to escape the clutches of darkness. An unexpected rescue by a hovering search helicopter comes as a beacon of hope.
Yet, in a chilling final shot, the dreadful ‘Death Ship’ continues its sinister journey, exuding an aura of death and revenge as ghostly voices resurrect in German, proclaiming once more, "Enemy in sight!" The freighter unfalteringly pursues its next victim, a passenger ship, ready to dismantle lives once more under the cloak of night.
