In summer, when the ocean ebbs at dusk, when the sand turns to glass and it becomes impossible to discern the difference between reflection and sky, the Tide Folk emerge from their pools. You might think, if you clamber on the cliffs searching for those tiny ecosystems the sea leaves behind twice a day, that you can see all there is to see—that you could, if you tried, touch the bottom of the pockets of water with your fingertip. And perhaps you’d be right. But something stops you from disturbing the shimmering surface, every time.

The Tide Folk, like shellfish, are scavengers. Emerging from their pools with seaweed-woven bags, they search for empty shells not yet crushed to powder; for dried bits of dulse baked by the sun to a toasty crisp; for discarded lobster claws, and feathers, and bleached bird bones. They use their long, nimble fingers to pluck up stranded sea snails and deposit them in glass jars filled with salt water, until the inner walls of each jar are dotted with climbing limpets, dog whelks, and periwinkles.

It is not for us to know what the Tide Folk do with their spoils. It is enough for us to see them at all, in that liminal space between sea and land, between day and night. Draped in green fringe, rough with barnacles, they trail the scent of salt water behind them. They move like the tide moves: slightly forward, then slightly back, making incremental progress across the rocks. When the wind blows, they pause, swaying back and forth.

As they collect their prizes, the Tide Folk keep a watchful eye on the progress of the sun, heavy on the horizon; they know that once the painted sky darkens to black, their way home will close. Inch by inch, they waft back across the rocks—bags clacking, jars sloshing—until they slip back into the water just before the first stars prick the velvet night. The pools swallow them whole without even a ripple, waiting for the waters to return. Had you not seen the Tide Folk with your own eyes, you might not believe they had ever existed at all.

But keep watching. Let your eyes adjust to the moonlight. For some Tide Folk—the very young, or the very old—have become distracted by unusual beauty. One has slipped a soda can tab on their thin wrist like a bracelet, adorning themselves in detritus. Another found an empty chip bag and licked the salt from it before turning it inside out and twisting it into a shiny necklace. A third holds a small glass marble in one trembling palm.

The Tide Folk know that all beauty is ephemeral, and that nothing is ever truly owned. They know that eventually—in one year or a thousand—the soda can tab will degrade and fall apart, the chip bag will shred into smaller and smaller pieces, and the marble will return to silica. And yet, they still allow themselves to be dazzled, and in doing so, they linger too long. As the sun sinks below the horizon, their kin call to them with mournful whispers: Shh shhhh, they call, knowing even now that it is too late for them to return. Perhaps those left on land hear their kin’s cry; perhaps they don’t. We cannot know if it was an accident or intentional, this stranding. But if you sit very still, and are very patient, you might see them: a darker shadow against the night, swaying slowly in the evening breeze.

In the early morning, when the sky blushes pink and the seagulls caw with ferocious glee, all you will find are a trio of stones trailing bladderwrack hair. You might admire the stones’ smooth surface, the way they fit in your hand. The way they shine wetly, like dark eyes. Maybe you will put them in your pocket and, when you get home, place them in a bowl or a jar to admire. And then you will find that, once dried, the stones have turned dull and pedestrian: ordinary rocks you might have picked up anywhere.

But then you will remember that someone once told you beauty is ephemeral, like dusk; that it is liminal, like a tide pool. That it is often hidden beneath a surface that reflects nothing but darkness. And you think that the Tide Folk who remained knew exactly what they were doing when they stayed on land to greet the stars.