Strange sounds from the old harbor and the case of missing children

 The noise was intolerable but Bobby Jenkins, known to his friends as 'Robj' couldn't be bothered. He was transfixed by the video playing alongside. It was that of an old harbor, some young children exploring it, and a couple of tourists using their crappy cellphone cameras to take videos of it casually. The shrill sound was bothering the camerapeople too, as they complained about something being off, perhaps it's a large shit coming this way, they said, or perhaps it's one of the lighthouse sirens. Or maybe it's a ghost, who doesn't want to kids to go into its holdout, somebody else suggested, from behind the camera.

Very soon, shrieks, loud shrieks, massive tide, lots of confusion and the camera shaking around, and darkness. Silence. Silence silence.

The news report that went along with it interviewed the guy who had videod the entire thing. He seemed shaken, for he was unable to stop talking, the reporter interrupted the nonstop verbal flow to point to the viewers a few important points about the case. A beachful of people had seen seven teenagers playing about and walking into the harbor to explore it, and a large tide had come by, then, nothing. The children had not been heard or seen again. Beach guards were called, the coast guards were summoned, and so were the police departments of the three nearby towns. Nothing. Nobody. Nowhere. Not even a piece of clothing, a cellphone, or a knicknack. It was as if they had never been there.

Could the children have been ghosts themselves, somebody suggested in the video. Were they apparitions or real children, for why had nobody else reported missing children in all the time that had passed since. The cops had asked everybody around to confirm, and no parents had come up yet. The ticket logs of the ships coming in and out showed no children that were unaccounted for. There was a slight chance they had come in private boats, but a search of the area showed there were no boats in tow, and nobody reported of seven missing children for many months on.

Some creepy, strange, otherworldly about it. It couldn't have been ghosts, obviously, yeah that was clear to everybody. They were far too...opaque, real...during the hours of the day, the sandcastles they made had been seen by many onlookers, photos of those from social media came out soon enough. Large fantastic castles, they were, not something a bunch of random teenagers would make, clearly. What sane parent would allow their children to go unaccompanied in strange terrain, and what of the shrilling sound, surely that had to do something with it. Was it some sort of 'replay' the ghosts did, play a high-pitched noise, and clear the canvas with the wave?

Or was it something more real, and sinister? A case of uncaring parents who were afraid of timing their admission of missing children against the tide of public opinion? Perhaps some human smuggling ring of sort. Could have been a scooby doo scenario, a smugglers' den underneath the old harbor, and they could have been family of the staff...of the smuggling company. Maybe they pushed a secret button and were comfortably inside the lair while everyone worried and searched around the island?

Robj found the sound interesting. He had heard it somewhere, it reminded him of some...thing, he couldn't quite point at what it was. He knew he could decode it, if only he had the context. He was browing through the collection of soundscapes he'd created over the past five years, trying to locate that piece of sound.