Jason stood over the footprints for a long moment without moving.
The tide had not reached them yet. They were still sharp enough to read: heel, arch, toes, each print pressed cleanly into the damp sand. Human. At least human-shaped. And definitely not his.
Wind moved off the water and cooled the sweat at the back of his neck.
He looked down the beach, then back toward the tree line, then at the prints again.
"Okay," he said quietly. "So either I'm hallucinating, or I've got company."
Neither option thrilled him.
He tightened his grip on the sharpened stick and started following the trail.
The prints ran close to the waterline, straight and unhurried, as if whoever had left them had known exactly where they were going. Jason matched his pace to them automatically, stepping around each impression rather than over it. He wasn't sure why. Instinct, maybe. Or the part of his brain still pretending this could be approached like a problem instead of a threat.
A few meters in, he slowed.
The trail passed the spot where he had been sitting earlier, feet in the surf, talking to the horizon like an idiot.
Jason stopped and looked at the sand beside his own older tracks.
They had been here.
Right here.
The thought landed hard enough to send a cold shiver through him.
He turned in a slow circle, scanning the empty beach. Pale sand. Moving water. The tree line beyond. No one. Nothing. Only the wind and the hush of the waves collapsing onshore.
Still, the back of his neck prickled.
"Great," he muttered. "Love that."
He followed the trail on.
The farther he went, the less he liked how deliberate it looked. The prints did not wander. They did not hesitate. They simply kept to the curve of the coast in a straight, purposeful line, as if the beach itself were a corridor and the destination had already been chosen.
Jason glanced over his shoulder once.
Still nothing behind him.
The open sky and empty shoreline should have been reassuring. Instead they made him feel exposed, like a rabbit that had strayed too far from cover and only just realized the field was full of hawks.
He kept walking.
Around the bend, the beach narrowed where a rise of black rock pushed out toward the sea. Vegetation spilled down over part of it in tangled green curtains, and beneath that overhang the stone opened into shadow.
A grotto.
The footprints led straight to it.
Jason stopped several paces short of the entrance.
"Well," he said, breathing a little harder now, "that's not suspicious at all."
The mouth of the grotto was wide enough for him to stand upright in, but the light died quickly past the first few feet. Inside, the air looked darker, cooler, almost thick. He could hear water dripping somewhere within, steady and hollow against stone.
He didn't move.
The smart option would be to leave. Go back to camp. Pretend he had not found evidence of another human-shaped thing walking around his island. But the same impulse that had dragged him up cliffs and into forests kept hold of him now. The need to know. The refusal to let a question sit unanswered when the answer might matter.
Jason swallowed.
Then he took a few careful steps forward.
The sand gave way to damp stone under his boots. The temperature dropped almost at once. Salt hung in the air, along with something older and mineral, the cold smell of rock that sunlight barely reached. His eye was still adjusting from the brightness outside, and for a few seconds the grotto was only shapes and glints.
"Hello?" he called.
His voice echoed once, then again, thinner each time.
Nothing answered.
Jason shifted the stick into both hands and moved deeper inside.
The grotto widened unexpectedly after the first narrow section. Light filtered down through cracks high above, thin pale shafts that broke against the stone floor and pooled in scattered reflections. At the center of the chamber lay a body of water, dark and still enough to look almost black from where he stood.
Jason stopped.
It wasn't large. More pond than pool, round and unnaturally quiet, its surface barely stirred except where droplets fell from the ceiling and spread brief rings across it.
For a second hope rose anyway.
Water.
He stepped closer, crouched at the edge, and reached out with his good hand. The surface was cold against his fingers. Clear, too. Clear enough that he could see down a little way before the light failed.
Jason lifted a wet fingertip to his mouth.
Salt.
He spat immediately and wiped his hand on his pants.
"Of course."
His voice sounded flat in the chamber.
"Why would anything ever be easy?"
He stood and looked around again.
The grotto offered nothing else. No packs. No tools. No sign of a camp. No half-hidden person waiting with a convenient explanation. Just wet rock, the salt pool, and the soft sound of water slipping from the ceiling.
Jason frowned.
He walked the perimeter once, slow and searching. The footprints were harder to make out on stone, but near the entrance they had clearly come in. That much he knew. And unless their owner had learned to levitate halfway through the cave, they should have gone out again.
They hadn't.
He returned to the edge of the pool and stared into it.
The water looked back blankly.
A small muscle in his jaw tightened.
"That's where you went," he said.
He hadn't meant to speak aloud, but the words came anyway.
Whoever had left the prints had entered the grotto. There was nowhere else to go. No hidden passage he could see, no second opening, no ledge tucked into shadow. Only the pool.
Jason crouched again, leaning just enough to look deeper. The water remained frustratingly clear near the top and unreadable below. He could not see the bottom. He could not tell how deep it ran, or whether it widened under the rock, or whether something might be down there right now, perfectly still, looking back up at him.
A ripple crossed the surface.
It took him a second to realize it had come from another drop falling from the ceiling.
Still, his heart had already kicked hard once in his chest.
He rose too quickly and had to steady himself.
"Nope," he said at once. "Absolutely not."
The word echoed back at him, ridiculous and thin.
He took a step away from the pool.
His mind, naturally, chose that moment to offer every possible version of what might be beneath the surface. A submerged tunnel. A hidden chamber. Some kind of amphibious person. Some entirely new nightmare custom-built by the same world that had already thrown storms, sharks, poison sap, and glowing insects at him.
He rubbed a hand over his face.
"I am not doing mystery salt cave diving half-blind," he informed the air. "Not today."
The cave remained unsympathetic.
Jason looked at the pool one more time, arms crossed now, the sharpened stick tucked under one elbow like that might somehow help if something with teeth came out of the water.
A sane person, he thought, would leave.
A braver person might jump in.
At the moment he felt like neither. Just tired, injured, and not nearly curious enough to drown over a clue.
He backed toward the entrance, not quite willing to turn his back on the pool until sunlight reached his shoulders again.
At the mouth of the grotto he stopped and looked over his shoulder.
The water lay dark and still in the center of the chamber, reflecting the cracks of light above it as if nothing strange had happened there at all.
Jason exhaled slowly.
"I'll come back," he said.
Whether that was a promise or a threat, even he wasn't sure.
He stepped out onto the beach.
Sunlight hit him full in the face after the dimness inside, warm and blinding and almost comforting. The sea looked harmless from here, all glitter and low foam and patient blue. Which only made the grotto at his back feel stranger.
Jason turned and studied the entrance from outside.
If something had gone in, it would have to come out eventually.
Wouldn't it?
He wasn't sure. That was the problem. Nothing about the island felt reliable enough to build assumptions on. Not the forest. Not the sea. Not the things that looked normal until he got close enough to realize they weren't.
Still, he knew one thing: he was not going into that pool blind, exhausted, and unprepared.
Not unless he ran out of better choices.
So he marked the place in his mind, counted the rock formations along the shore, the shape of the overhang, the way the vegetation draped over the entrance like a curtain. Then he started back down the beach toward camp, slower this time, glancing once over his shoulder before the curve of the coast finally hid the grotto from view.
The footprints remained behind him in the sand.
A trail leading from nowhere to dark water.
By the time Jason reached the tree line again, the unease had settled properly into his bones.
He was not alone.
And whatever else that meant, it meant the island had just become much, much bigger.