The Aleph of Oblivion

 (from the cycle of stories "Notes on Files leading to other dimensions")

The other day, when autumn rain tapped against the shutters and the tea in my cup had long gone cold, one of those rare visitors appeared at my door—the kind who comes not to play, but to test whether the world still remembers the rules of forgotten realities.

He placed upon the table a chessboard—not the one gathering dust in my corner, but a strange one, with hairline cracks running along its files, as though someone had once tried to pry it open with a knife.

"They say you play Superpermutation d8 Chess?" he asked, producing an eight-sided die upon whose faces I discerned unsettling numerals.

The game began ordinarily enough—recursive swaps and teleportations of kings 

followed the script the Universe itself had written—until my 42nd move, when this position arose before us:

I clenched in my palm the octahedral symbol of eternity—this small yet perfect Aristotelian cosmos—and cast it forth to behold the number already predestined in one of the Library of Babel's infinite volumes. The die's fall did not generate my move, but merely unveiled a chapter written before me...

The Oracle showed 6.

"The f-file—The Aleph of Oblivion," whispered the Stranger. Suddenly I realized my rook on c7 was no rook at all, but the force of "The Fractal Wind," carrying not just pawns toward damnation.

42. Qe7-f6#

When I made the fateful move (Qe7-f6), the pieces began exchanging places of their own accord, as though rearranged by an unseen hand. The knight shifted to f6, delivering mate in concert with the queen, yet...

"This is not the end," my guest smirked. "Merely the first move in another game—one played upon a board the size of the Universe."

By morning, only the die remained by the door. Where the number 6 should have been, there was but a crack tracing the contours of the letter ξ.

P.S. Should you attempt to repeat my error—seek not the checkmate. Seek the one who placed the board.