The first time it happened, nobody believed her.
At exactly 2:13 a.m., the water in Hollow Lake rippled even though the wind was still. The moon hung perfectly above it, like a silver coin dropped into ink, and from the dark surface came a sound low, hollow, and rhythmic. Almost like a heartbeat.
Mara Weston froze on the dock, her flashlight trembling in her hand. The sound pulsed again — thud… thud… thud — echoing across the water.
Then it stopped.
She waited, her breath fogging in the cold, until she convinced herself she imagined it. The lake always had stories the drowned miner, the old town beneath the waterline, the "echo wells" that trapped sound. She told herself it was just that. A story.
But the next morning, the lake was lower.
Only by a few inches, but enough to expose a jagged metal shape near the shoreline a rusted hatch, the kind you'd see on a submarine. Except there had never been a submarine here. Hollow Lake was landlocked, and far too small for anything like that.
She took photos and texted her brother, Eli, the town's night patrol officer.
Mara: "The lake dropped. Found something weird near the north dock. Looks man-made."
Eli: "Stay away. Could be a septic cover or debris. I'll check it later."
He didn't. And that night, the sound came again. Louder. Closer.
This time, Mara recorded it a thirty-second clip of deep, metallic pulses that grew faster near the end. She uploaded it to a local community forum under the title "What's under Hollow Lake?"
By morning, the post was gone. Deleted.
Her account too.
When she called Eli, he didn't answer. Instead, a text appeared an hour later.
Eli: "Stop posting. You don't want to be part of this."
No context. No explanation.
By sunset, police tape surrounded the lake, and a team in unmarked vans was lowering equipment into the water. The town paper called it a "chemical spill assessment."
But Mara had seen one of them lift a heavy, rust-stained hatch out of the mud the same one from her photo.
And beneath it, just before they covered it, she swore she saw something written on the metal in faded red paint.
"Do Not Open Twice."
Then the sound came again but this time, it was coming from the shore.