23

The valley lamps had steadied again, but the manor felt tighter than ever. Wesley laid the insulated glove on Kasparsnow’s desk, and Kasparsnow shut the drawer.

Coalridge was sent to watch the corridors. Pawnsworth and Emily Brent were told to remain with the others. Even Magnus Carolsen was told to keep his games in the hall where they could be seen.

It might have worked, if the front doors had not opened just after noon.

A small elf stepped in, stamping snow from his boots, and looked about him with the air of a man who had been sent to deal with incompetence.

“Hans Nissemann,” he announced. “From the North Pole. I am here because the guidance field keeps blinking like a bad candle.”

He caught sight of the bare tree and made a sound of pure disgust.

“So,” he said. “Someone is trying to ground Abdusantarov.”

You stared. “Who?”

“Santa,” he said. “You call him Santa, but that's just a nickname. His full name is Nodirbek Abdusantarov. Anyway.” He waved a hand. “If your Star is not back by tonight, he cannot launch. No launch, no gifts.”

Kasparsnow pointed at the glove. Hans took it.

Kasparsnow showed him the glove. Hans turned it over once.

“Someone here knows their way around wiring,” he said.

Behind him, Magnus glanced at the chessboard on the side table.

“Well,” he said, “at least they like tidy endings. This is a mate in 1.”

Hans looked at the board, then back at the room.

“And you want to know how it got there,” he said. “Seven last moves.”

He set the board square and straightened.

“Well,” he said, “which one of you is Grinchuk?”

There's a mate in 1 in this position. Given that this position could be reached in a legal game of chess, and that there is only one unique answer to this problem, what were the last 7 single moves played?

To submit your answer, use the interactive board below:

• Reset the board to the position as it was 7 half-moves ago.
• Play out the 7 moves in the correct sequence to reach the starting problem position.

(Note: A single move, also known as a half-move or ply, means one move by one side.)

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