"Incident one hundred miles off the coast of Guadalcanal. Time: the present. The United States naval destroyer on what has been a most uneventful cruise. In a moment, they're going to send a man down thirty fathoms and check on a noisemaker - someone or something tapping on metal. You may or may not read the results in a naval report, because Captain Beecham and his crew have just set a course that will lead this ship and everyone on it - into The Twilight Zone."
In 1963, a U.S. Navy destroyer is on a routine patrol off Guadalcanal, when sonar picks up the sound of metallic clanging beneath the waves; the crew speculates that it sounds like a hammer.
It's soon discovered that a submarine is on the ocean floor, but inquiries to naval command reveal no recent sinkings or incidents of any kind in the area. A joking suggestion from some of the crew that the sub may be haunted sends an anxious and bewildered Chief Bell, who had been feeling unwell for a couple of days before, into a frenzy of bizarre behavior, including fainting spells. The destroyer's commander, Captain Beecham, orders the ship's diver, McClure, to investigate. They find out that it's an American submarine, and there is definite hammering coming from inside. "Who could be inside that sub?" wonders a crewman. Beecham replies, "Somebody who dies damn hard!" The revelation that the submarine is American sends Chief Bell into an even greater neurosis, who begins to see apparitions of dead sailors beckoning him to come to them. The ship's doctor unsuccessfully tries to convince Bell that he is just having nightmares, and reports to the captain that Bell is experiencing effects of psychological trauma usually caused by wartime experiences.
McClure later discovers the number of the submarine, "714", which Beecham is able to identify as belonging to a submarine that was sunk during the Battle of the Eastern Solomons, almost 21 years ago. Although stunned at the idea that someone inside the submarine could still be alive, Beecham asks naval command for a submarine rescue operation. Upon returning to the ship, the diver gives Beecham a dog tag he recovered from the ship, which is revealed to have belonged to Chief Bell.
When Beecham shows the dog tag to Bell, he begins to recollect that he was indeed on that same submarine 21 years before during the battle, when it was surrounded by enemy Japanese ships. Bell recalls that he had been a signalman, and had dropped a signal light while attempting to change the infrared filter in the middle of night, causing the filter to fall off. As a result, Japanese ships were able to see the submarine and attack it mercilessly. Bell fell off the submarine amidst the shelling, and although the captain took the submarine underwater, it sank due to the Japanese attack. Bell was later rescued by an American destroyer that came into the area. Bell tells Beecham that he now understands that the clanging noise is being made by the dead crew underwater, who know he is above them right now and are demanding that he join them in death. Bell is overcome by survivor guilt and feels responsible for sinking the submarine, as well as for being the only one of the crew to escape. Despite Beecham's efforts to explain to Bell that he wasn't guilty of cowardice or responsible for the sinking of a submarine already surrounded by enemy ships, Bell races to the deck and jumps overboard. The ship's crew are unable to save Bell or recover his body from the water.
Later, McClure accompanies the rescue mission into the drowned submarine. Upon returning to the ship, he reports to Beecham that he had found the periscope shears cut in half, with one swinging back and forth. When Beecham asks him to confirm that this was the clanging noise they had heard, McClure agrees, but adds that he had also seen the remains of eight dead sailors, one of whom was holding a hammer in his hand.
"Small naval engagement, the month of April 1963. Not to be found in any historical annals. Look for this one filed under 'H' for haunting - in the Twilight Zone."
Columbia Broadcasting System (CBS) (in association with)
Columbia Broadcasting System (CBS) (1959) (USA) (TV) (original airing)
The exterior shots of the ship used in this episode were of the The "Mighty Mux" USS MULLINNIX DD-944, A Forrest Sherman class destroyer. The interior shots were done on board the USS-Edson DD946. The Edson is now on display at the Saginaw Valley Naval Ship Museum in Bay City MI.
Mike Kellin portraying the main character, Chief Bell, died 26 August 1983, the ship used for exterior shots in the episode was decommissioned 11 August 1983. Simon Oakland, who portrayed the captain, died three days later on 29 August 1983.
The hull number for the sunken submarine, 714, was not actually used by the Navy until the construction began on the USS NORFOLK SSN714 in August of 1979. In the episode, it was mentioned that the submarine was built in 1941. Those built in 1941 had "21x" hull numbers.
A fathom originally was measured by a man's outstretched arms, and was later standardized as 6 feet in the universal English system. Therefore the title translates as "The 180-foot Grave."