“The pool seems higher today,” Laura remarked, tilting her head back to observe the crystalline water suspended impossibly above ground level.

“It’s always changing,” Marcus replied without looking up from his book. “Yesterday it was barely knee-height. Tomorrow it might touch the clouds.”

The floating pool had appeared in their neighborhood three weeks ago, defying physics and reason. Its transparent walls held masses of shifting water that sometimes rippled with otherworldly lights.

“I’m going in,” Laura announced, already climbing the ethereal steps that materialized beneath her feet.

“You know what happened to Thompson when he—” Marcus started.

“When he what?” Laura called down. But Marcus had vanished, leaving only his open book face-down on the grass.

The water was perfect - not warm, not cool, simply present. Laura dove deeper, her movements creating barely a ripple. Strange symbols danced across the glass-like walls, rearranging themselves into patterns that almost made sense before dissolving again.

“Welcome back,” a voice echoed. Laura spun around to find herself face-to-face with… herself. But this Laura was older, with silver-streaked hair and laugh lines around her eyes.

“You’re taking this rather well,” her older self noted. “The first time I was here - which is now, for you - I nearly drowned from shock.”

“Where exactly is ‘here’?” Laura asked, discovering she could speak normally underwater.

“The In-Between,” older Laura replied. “A fold in reality where all possible versions of ourselves intersect. Look there.”

Through one wall, Laura saw Marcus still reading his book. Through another, she watched herself as a child learning to swim. Through yet another, an elderly Laura taught her grandchildren to float.

“Why show me this?”

“Because you’re about to make a choice,” her older self explained. “In exactly two minutes, you’ll notice a small tear in the pool’s fabric. You can either swim through it to a different timeline or return to your own.”

“What did you choose?”

The older Laura smiled mysteriously. “That’s not how it works. Each choice creates its own reality. My choice was mine. Yours must be yours.”

Right on cue, a shimmer appeared in the corner of Laura’s vision - a tiny rent in the structure of the pool itself, leading to… somewhere else.

She hesitated, floating in the impossible water. Through one wall, she could still see Marcus waiting below, probably wondering why she was taking so long. Through the tear, she glimpsed flashes of unknown possibilities.

With a decisive stroke, Laura swam downward and emerged from the pool, water streaming from her hair.

“Nice swim?” Marcus asked, finally looking up.

“Nothing special,” Laura replied, settling beside him on the grass. “Just water being water.”

Above them, the pool shifted imperceptibly higher, its waters holding countless untaken paths, while somewhere - or somewhen - another Laura was beginning an entirely different story.

Marcus turned a page in his book: “The Invisible Cities” by Italo Calvino.

“You know,” he said thoughtfully, “I read somewhere that swimming pools are just domesticated oceans.”

Laura laughed, but her eyes never left the enigmatic structure hovering overhead, wondering if perhaps all choices existed simultaneously, like water held in an impossible container, waiting to spill into reality.