18

The group enters the abandoned research station, its air unnaturally still. David sweeps his scanner across the room, his expression tightening. "The gravitational distortions are stronger here—closer to the black hole’s field than I thought. This place is a nexus."

Santa steps forward, his voice steady. "And Grinchuk’s been here. Look."

At the center of the room sits a chessboard, glowing faintly. Around it, old machinery hums with residual energy, and schematics line the walls—crude diagrams of the TSC. Magnus squints at the chessboard, the pieces oddly arranged.

David frowns, examining the nearby console. "These systems are running feedback loops. He’s been using this station to amplify the black hole’s gravitational waves. If he keeps this up, the TSC will lose its ability to control time dilation entirely."

The group gathers around the glowing chessboard, its pieces frozen mid-game. Wesley points at it, frowning. "Another of Grinchuk’s puzzles?"

David scans the board. "It’s worse than that. The TSC’s distortions are pulling this board between two timelines – one where checks didn’t exist, and one where they did. The result? Checks are illegal unless it's checkmate."

Santa steps forward, his voice steady. "Then let’s fix it. Solve the puzzle, and let’s restore some order to this chaos."

This is a checkless helpmate. Any check that's not a checkmate is against the rules. Both players still cooperate to achieve checkmate, but without checks. Consequently, a check is also considered checkmate, and therefore legal, if the only responses are non-checkmating checks! Black moves first, then White. Four moves each. White's last move must be checkmate. See the Checkless category if you're confused. Here's a link to the position on Lichess, and here's Offerspill's Discord server.