The beach was nearly empty when Daniel and Emily arrived. The afternoon crowd had gone, leaving only a few people walking along the water and an old fisherman seated beside a pile of nets.
Daniel was looking down at the wet sand when he spotted something small near the edge of the surf. It was dark and glossy, half covered by sand.
“Looks like a little fish,” he said.
He crouched to get a closer look. Before he could touch it, the shape shifted. Something curled around his ankle.
Daniel sprang back with a shout. A quick, sharp sting made him lose his balance, and he landed hard on the sand. Whatever had grabbed him slipped away with the next wave.
Emily hurried over. “Daniel, are you all right?”
He nodded, but his face had gone pale. A mark was forming just above his ankle: two small punctures surrounded by a dusky ring. The skin nearby began to swell.
“I didn’t see what it was,” he said. “It was gone before I could look.”
The fisherman had come closer. He studied the mark without touching it, then turned his gaze toward the water.
“I’ve seen something like that once,” he said quietly. “A long time ago.”
Emily put an arm around Daniel. “What happened?”
The fisherman hesitated. He told them that another visitor had been bitten near the same stretch of shore years earlier. The man had gone home that evening, apparently feeling well enough to leave. By morning, his rented room was empty. His belongings were still there, but no one ever found out where he had gone.
“That doesn’t tell us anything,” Emily said, though she tightened her grip on Daniel’s arm.
The fisherman looked at the incoming tide. “Maybe not.”
She didn’t wait for another explanation. Emily helped Daniel to the car, and they drove to the nearest clinic.
At the hospital, a nurse cleaned the small punctures and asked Daniel several questions: where he had been standing, how quickly the swelling began, and whether he had felt dizzy or unwell. The doctor examined the area and ordered a scan to check the tissue around the bite.
For a while, the results seemed ordinary. There was swelling, but nothing that clearly explained what had happened. Daniel rested on the examination bed while Emily sat beside him, still wearing sand on the hem of her trousers.
Then he felt a faint flutter beneath the bandage.
“Did you feel that?” he asked.
The nurse checked the dressing. She found no movement and reassured him that the sensation could come from the irritated skin. But Daniel had felt it distinctly—like a tiny pulse just below the surface.
The doctor returned with the scan images. One of them showed a narrow shadow near the wound. The team looked again, adjusting the view and comparing it with the earlier image. The shadow seemed to shift between scans, though no one could say whether it was real or caused by the image.
“Could it be a splinter?” Emily asked.
“Possibly,” the doctor replied. “We’ll take another look before deciding what to do.”
They prepared a closer examination. As the nurse carefully loosened the bandage, a cold drop of water slid from the edge of Daniel’s ankle onto the white sheet.
Emily stared at it.
The room was dry. Daniel hadn’t showered, and the wound had already been cleaned.
The doctor paused, then leaned closer. Beneath the faint purple mark, something moved once—so slightly that Daniel wondered if he had imagined it.
The nurse stepped back and called for the doctor to look again.
Outside the hospital window, the evening tide rolled toward the shore. By the time the next scan appeared on the monitor, the unexplained shadow was gone.
The doctor studied the image in silence.
Daniel turned to Emily. “What did they find?”
No one answered right away.
