20

The group descends deeper into the cavern, the hum of the Chrono-Sleigh growing louder with every step. The walls shimmer and warp as gravitational distortions ripple through the space, bending light into eerie, flowing patterns.

David glances at his scanner. "We’re almost there. The TSC’s power is peaking, and it’s feeding straight into Grinchuk’s sleigh."

Ahead, the cavern opens into a vast chamber. At its center, the Chrono-Sleigh sits on a platform surrounded by swirling beams of energy, its structure vibrating as it draws power directly from the black hole’s ergosphere. The light here bends unnaturally, making it feel as if the sleigh exists in multiple places at once.

Magnus whistles under his breath. "I’ve seen dangerous machines before, but this… this feels alive."

Santa steps forward, steady as ever. "Then we stop it before Grinchuk activates it. David, what are we looking at?"

David studies the console nearby, his voice tight. "He’s locking the timeline into a loop. If the sleigh launches, it’ll tether itself to the black hole and fracture time permanently."

Wesley points at the controls. "So what’s the plan?"

Before David can answer, the console flares brightly, projecting a distorted chessboard into the air. The pieces shimmer and shift, but something is wrong. Magnus tilts his head. "Where’s the Black king?"

David’s scanner beeps erratically. "The gravitational distortions have erased the Black king. Be cautious, this board is unstable."

Santa steps closer, studying the glowing projection. "Then we need to restore it. Find where the king belongs, and give checkmate."

It's White to move, but the Black king is missing. Place the Black king so that White can force a mate in two moves. White to move, then Black, and White's second move is checkmate. Note that this is not a helpmate, so White must be able to force a mate regardless of Black's response. Provide the square at which to place the Black king, followed by a comma, and White's first move leading to the mate in two.

Example format: e8, Ra1