Three Knocks Beneath the Sea

Silence has a texture under the sea. It isn’t empty—it breathes. It hums against the steel, curls into the corners, whispers in your skull until you start to hear your own blood. We were two miles beneath the surface when I heard it.
Three knocks.
Measured. Solid. Familiar. It reminded me of the way my grandpa used to knock on my door after making the long drive to see me.
I sat up in my bunk, heart pounding so hard I felt it in my teeth. No one should have been awake except Reyes on night watch. The rest of the crew slept in their metal coffins, their breath feeding the recycled air system.
The clock read 02:46.
Three more knocks. Louder now. On my door.
I stared at it—the trembling hinge, the echo traveling through the walls—and said, “Who’s there?”
Nothing.
Of course it was nothing. The embarrassment came fast, hot. Calling out to nothing. Just the deep, eternal hum of the Odyssey and the distant groan of the hull flexing against pressure that could crush us in a heartbeat.
I stood, bare feet against cold metal, and opened the door.
The corridor glowed dull red under the night lights. The air tasted of oil and salt. No one.
Only three small wet circles on the door—like fingertips.
I touched one.
It was freezing.
Reyes jumped when I entered the control room. “Jesus, Harper,” he said, clutching his chest. “What are you doing up?”
“Someone knocked on my door.”
He frowned. “No one’s moving around. Everyone’s accounted for.”
“Then what did I hear?”
He hesitated, then tapped the sonar display. “I’ve been getting something weird. A return echo—small. Moving along the hull.”
The pulse slid across the screen. It wasn’t static. It shifted.
“Could be current,” he said.
“At two miles down?”
He didn’t answer.
A flicker. Then nothing.
“I’m checking the observation chamber,” I said.
“Harper—”
But I was already walking.
The chamber buzzed softly. The external camera showed nothing but blackness—endless, patient black.
I leaned closer. My reflection hovered over the void, pale and unreal.
Then something moved.
A distortion. Like heat shimmering in air.
I flicked on the floodlights.
The hull burst into view, silver-gray and sweating condensation. Near the edge of the frame—there.
A handprint.
Pressed into the metal.
I froze.
And through the steel, unmistakable, I heard it.
Knock. Knock. Knock.
“Reyes!”
He arrived breathless. “Listen,” I whispered.
Three soft blows echoed through the ship, settling deep in my bones.
“That’s impossible,” he said. “We’re two miles under.”
The Captain woke everyone. Ten of us gathered in the mess, whispering theories—pressure shifts, hull expansion, sonar ghosts. No one mentioned the fact that we had all heard it.
Porter squinted at the monitor. “Zoom in.”
The feed magnified. Something shimmered against the hull, pulsing faintly.
“It’s moving,” he said.
The Captain ordered more light. The shimmer vanished.
Then a dragging sound scraped across the steel.
Knock. Knock. Knock.
I had never seen fear spread so fast. These were people who had faced death without flinching. That night, none of us slept.
At 6:00 a.m., I found Porter shivering in the mess.
“You look like hell,” I said.
He raised his hand.
Three red circles marked his palm.
“It knocked back,” he whispered. “From inside the pipes.”
My stomach twisted. “Inside?”
He nodded. “It’s in the sub.”
I laughed. I don’t know why. A stupid, brittle sound—like this was all a prank.
The look on his face snapped me back.
“Maybe it was your echo,” I said.
“Maybe.”
Neither of us believed it.
Two men disappeared the next night.
No alarms. No breach. Just gone. Bunks empty. Boots still by the door. Reyes found a puddle of saltwater near the aft chamber. No leak above it.
Three shallow finger dents pressed into the floor.
“We’re surfacing,” the Captain said.
The engines failed. Lights dimmed. Emergency red flooded the halls.
Knock. Knock. Knock.
Porter’s scanner pinged. “Something’s in the wall.”
The steel bulged outward, slow as a breath. Then it split.
No water came.
Black vapor spilled out—alive, veined with faint light. A face pressed through it. Almost human.
It raised a hand.
Three knocks.
Then laughter.
My laughter.
The bulkhead sealed. Silence returned.
Later, the intercom crackled. “Harper,” Porter whispered. “It says you shouldn’t have turned on the lights.”
The line went dead.
We found him floating, eyes open, a shadow behind him shaped like a man.
By morning, half the crew was gone.
As we ascended, Reyes stared at the sonar. “It’s following us.”
Two blips. Perfectly aligned.
The knocks grew louder. Closer.
Then the whisper came through every vent, every thought:
Don’t open the door.
I did.
Blue light flooded in. Beautiful. Warm. Familiar.
Like home.
Like my grandpa’s knock.
I laughed as the water filled my lungs.
I laughed as the light faded.
I laughed as I knocked three times on the outside of the submarine.