That year the tide drew back further than anyone could remember.

The sea floor lay bare, wet and black, littered with shells that had not made it home. On the beach a ring of children were prodding an overturned sea turtle with a stick. Urashima drove them off and carried the turtle back into the water. Before it sank it turned and looked at him — and no turtle has ever had that look.

The next day, at the same hour, it swam back to the shore by itself and said: my lord asks you to come.

The sea has layers. Ten fathoms down you can still see your own hand. At a hundred, blue turns to a green so dark it is almost black. Below that the light stops — it does not fade, it stops, like a door closing.

Urashima assumed that behind the door it was dark. He was wrong.

Behind the door was another kind of light, and it did not come from above. It came from below. The whole city is built of mother-of-pearl: shell lining glows on its own in deep water, green and violet and gold, layer over layer, turning slowly with the current. Two characters are cut into the gate — Dragon Palace.

On land a wave arrives and then withdraws. In the palace waves never withdraw; they are only replaced.

One falls, and the wave above drops in to fill the space it left. Nothing is ever still down here — what looks like an ending is only a change of water.

The board works the same way: 8 or more of the same thing in the water at once pays, with no line to form; then it clears, the ones above fall in behind it, and a single spin settles several times over. What a player watches is never one result. It is a tide.

Before the banquet Urashima was brought before the lord of the city.

Watatsumi — the sea god. In human form: a white beard to his chest, a crown inlaid with whole sheets of nacre, robes drifting in the water like another kind of seaweed. Above his open palm a pearl hung quite still, neither falling nor floating away, with a number cut into its face.

“Nothing in the sea is large or small,” he said. “It counts from the moment it reaches you.”

He opened his hand. The pearl did not sink. It broke apart into several, and they came down through the water in front of him, each carrying a number of its own.

Those are the dragon pearls. They do not have to be caught, and they do not have to be lined up with anything. They only have to be on the board when a win lands — ×2 to ×20.

The banquet began. Sea bream and flounder danced, an octopus beat eight drums at once, and jellyfish hung from the beams opening and closing as lamps. Every light in the hall had grown there. Not one of them was fire.

Otohime sat at the head. On a stand at her side was a box: black lacquer, gold tracery, tied with a red cord. In the whole long evening the box was never once mentioned.

In the end Urashima asked.

“That is the tamatebako,” she said. “One of them is a gift.”

She paused.

“4 of them is a door.”

How long he stayed after the door opened, Urashima could never say.

The palace is not like the shore. On land a day is spent and gone; here it is not. Everything he gained stayed with him — ×2 to ×500 — and carried into the next thing; no hour ever started again from nothing. 15 banquets, each heavier than the one before it.

For a long while he took that for the hospitality of the place. Later he understood that it was the palace — that time here only accumulates, and never resets.

Now and then more boxes were carried in — 3 of them and the banquet ran another 5 banquets, with nothing already stacked given back. The door was already open, so it stayed open.

In the end he wanted to go home.

Otohime did not keep him. She put the box into his hands and said the thing she had said at the gate: open it whenever you like — only, once it is open, there is no way back.

The turtle carried him to the same stretch of sand. The tide was going out as it always had, and there were children on the beach as there always were — but the village had another name, and a pine he had never seen was growing where his house had stood. He asked an old man passing by whether he knew of someone called Urashima. The old man said: that was three hundred years ago.

Urashima sat on the sand a long time. Then he untied the red cord.

White smoke rose out of it. It was not smoke. It was the three hundred years he had been given in the palace, repaid all at once.

So the box reaches the player closed.

Whether you gather 4 of them and let it open on its own, or, where the operator offers the bonus buy, spend 100× your stake and open it now — that part is yours to decide, not the sea god’s.