In 1963, an U.S. Navy destroyer is on a routine patrol off Guadalcanal when sonar gets a sound underneath the waves; the crew say that it sounds like something banging on metal.
They find a submarine on the ocean flooring, yet questions to naval command reveal no recent sinkings in the area. A kidding suggestion from some of the crew that the sub might be haunted sends an anxious as well as confused Principal Boatswain's Mate Bell, that has actually been feeling unwell for a number of days, right into a craze of bizarre behavior, consisting of passing out spells. The destroyer's leader, Captain Beecham, orders the ship's scuba diver, McClure, to examine. They learn that it is an American submarine, and also the metal noise is coming from within. When McClure bangs on the submarine hull, the steel banging restarts in seeming reaction. Principal Bell starts to see apparitions of dead sailors beckoning him. The ship's medical professional unsuccessfully attempts to encourage Bell that he is simply having headaches, and also reports to the captain that Bell is experiencing results of emotional injury typically caused by wartime experiences. He discovers a stack of algae in the spot where Bell saw the phantoms.
McClure later uncovers the number of the submarine, "714", which Beecham recognizes as belonging to a submarine that was sunk throughout the Fight of the Eastern Solomons twenty years in the past. Although shocked at the concept that a person inside the submarine might still be alive, Beecham asks Pacific Fleet command for an emergency-priority rescue procedure. Upon returning to the ship, the diver gives Beecham a dog tag he recovered from the ship, which belongs to Principal Bell.
When Beecham shows the pet dog tag to Bell, he states that he was a signalman on a submarine during the war. He dropped a signal light while attempting to change the infrared filter at night, triggering the filter to fall off. Consequently, Japanese destroyers saw the light as well as attacked. Bell was blown into the water by the shelling. The captain got a dive, yet depth fees sunk the boat. Bell, the sole survivor, was later on saved by an American destroyer. Bell informs Beecham that he now comprehends: his dead shipmates know he is above them today and are demanding that he join them. Bell relapses by survivor shame, and also claims "I sunk that sub. I'm accountable." Despite Captain Beecham's efforts to encourage Bell that his error did nothing, that a boat captured on the surface area as well as bordered by opponent ships was currently doomed, Bell dons his old pet dog tags, races out on deck, and also leaps overboard, yelling, "They're calling muster on me!" The destroyer's crew are not able to conserve Bell or find his body.
Later, McClure comes with the rescue objective right into the submarine. Upon going back to the ship, he reports to Beecham that the boat was a wreckage within, and also no person was left alive. Inside the control area, he had discovered the periscope shears halved, with one swinging back and forth. When Beecham asks him to verify that this was the clanging sound they had actually heard, McClure agrees, but adds that he had likewise seen the remains of 8 dead sailors; one was holding an embed his hand.