The story of how the hatch came to be open begins on a bleak November morning in 1925, when the English Channel was in the grip of a storm. Waves heaved and crashed against one another, jagged and foaming like mountains of steel-grey water. The wind howled across the deck of the Swedish collier SS Vidar, driving sheets of icy spray over her bow and rattling the rigging until it sang like tortured wire. Each time the ship’s nose plunged into a trough, green water swept the forecastle and thundered aft in torrents, drenching the crew and hammering the hatches. Her black hull groaned, her engines fought valiantly against the swell, but still she pressed on, bound eastward for home.

The men on watch hunched against the gale, eyes stung by salt, boots braced against the lurch and roll. Then it came — not the rhythmic crash of wave against steel, but something deeper, stranger. Two heavy, sickening jolts reverberated through her bows in quick succession, as though the ship had struck some submerged rock or unseen beast. The entire vessel shuddered, timbers creaked, loose tools clattered across the deck. Shouts rose in confusion as the crew stumbled to their feet, gripping the rails against the violent motion.

The master stormed from the wheelhouse, his oilskin whipping in the wind, face set in a scowl as he scanned the chaos of the horizon. There was nothing but storm: a world of heaving grey water and white spindrift, no masts, no smoke, no wreckage to explain the hammering blows that had jarred his ship from stem to stern. He spat seawater from his lips, shaking his head. Depth charges, he muttered — the Navy and their endless exercises, careless of merchantmen. Nothing more than that.

Below, inside HMS M1, chaos reigned. The impact had torn open the hull where the experimental twelve-inch gun jutted from the casing. Water surged through the breach, flooding forward compartments. The alarms shrilled, men shouted, the lights flickered. Lieutenant Commander Alec Michael Carrie seized the periscope handles, his face tight as he demanded reports. The answers were grim: flooding uncontrollable, compartments lost. The sea was pouring in faster than they could fight it.

“Open the hatch!” Carrie’s voice cut through the chaos like a whipcrack. In the control room, men hesitated for the briefest second, knowing the order was as much a death sentence as it was a chance at life. If it stayed sealed, they would drown like rats in a cage. If it opened, perhaps a handful might escape — but the sea would come for the rest.

The wheel turned under straining hands, metal grinding in protest. Then, with a shriek of tortured hinges, the conning tower hatch broke free. A blast of air and seawater crashed downward, flooding the compartment with a deafening roar. Men flinched, blinking against the sudden spray and the stinging cold. Faces tilted upward into that pale slit of daylight, eyes wide with a mixture of terror and desperate hope. For a moment, freedom seemed within reach.

One after another, four men clawed their way up the ladder and out into the storm. The sea met them like a living thing, hurling spray across their faces, tearing at their oilskins. They tumbled onto the slick casing, coughing, gasping, gripping at handholds as the submarine bucked beneath them. Behind them, water poured through the hatch in a torrent, hammering the control room below, flooding the gauges and extinguishing the lights with sharp, sparking pops. The M1 shuddered like a wounded beast, tilted bow-down, and began her fatal plunge.

Inside, men threw their weight against the hatch wheel, but the sea’s strength was greater. It was too late. With a groan of surrender, the submarine slipped beneath the waves, the open hatch a gaping wound that dragged her to her grave.

Above, the four survivors were left to the mercy of the Channel. The storm tossed them like driftwood, waves smashing over their heads, filling their mouths with salt and foam. They clung to life with raw hands, screaming into the wind, their voices ripped away before they could carry more than a few feet. Through the spindrift they saw the collier Vidar, a smudge of black against the grey horizon, its stern lifting and falling as it pulled away into mist. They waved, shouted, begged to be seen. But no one turned. No one came.

The sea grew colder, the minutes stretched into eternity. Their limbs numbed, their cries weakened. The Channel is merciless in November, indifferent to human struggle. One by one, the shouts grew faint, swallowed by the gale until only the crashing surf remained. Four men who had fought their way clear of the steel coffin were taken just the same, their final cries vanishing into the endless roar of the storm.

Below decks, beyond the reach of the storm, the men who remained were entombed behind their own watertight doors. They had done everything their training demanded — sealing bulkheads, slamming home levers, isolating compartments to buy the submarine precious minutes of life. It had been the right thing to do, the only thing to do. Yet now those very precautions were their cages. The steel doors, once their safeguard, were locked fast, unyielding, and the sea pressed in on every side.

The electric lights flickered, sputtered, then died, leaving the compartments bathed in choking darkness. Only the groan of tortured metal and the dull thunder of the storm filtered down through the hull. Men clung to bulkheads, their bodies slick with sweat, as the air thickened around them. At first it was merely stifling, hot and close, but soon every breath burned like fire in their lungs. The invisible weight of carbon dioxide crept higher, heavier, smothering.

Some men cursed, pounding fists against the doors, their shouts echoing back at them like cruel reminders of their prison. Others whispered hurried prayers, fingering small crosses or clutching keepsakes in trembling hands. A few sat in silence, backs against the cold steel, their faces pale in the dim emergency glow that lasted only minutes before fading to black. They could hear one another’s breathing — ragged, shallow, desperate.

Time became a blur. Each gasp felt thinner, each heartbeat louder in their ears. Sweat dripped, lungs burned, and minds reeled in dizziness. One by one, voices faltered. The shouting stopped. The prayers grew faint. In the suffocating dark, men slumped where they sat, sliding slowly to the deck plates, their bodies surrendering at last.

The submarine held them gently in her iron embrace, sealing their fate. Once a weapon of war, HMS M1 had become a steel coffin on the seabed, a tomb for sixty-nine souls whose last fight was not against an enemy, but against the sea, the air, and the inexorable passage of time.

For decades the Channel kept the secret. Then divers found her again, looming out of the gloom with her great gun lying useless on the sand. They traced the lines of torn steel, shone torches into the silent tower. And there it was—the hatch, unmistakably open. It had not been forced by collision or by the sea. It had been opened from within.