Party Police.

Chapter Twenty-Six.

The next chamber was so dark the four couldn't see anything at all. But as they stepped into it, light suddenly flooded the room to reveal an astonishing sight.
They were standing on the edge of a huge chessboard, behind the black chessman, which were all taller than they were and carved from what looked like black stone. Facing them, way across the chamber, were the white pieces. Harry, Ron, and Hermione shivered slightly— the towering white chessmen had no faces.

"Now what do we do?" Harry whispered.

"It's obvious, isn't it?" said Ron. "We've got to play our way across the room." Behind the white pieces, another door could be seen.

"How?" Hermione asked nervously.

"I think," said Ron, "we're going to have to be chessmen."
He walked up to a black knight and put his hand out to touch the knight's horse. At once, the stone sprang to life. The horse pawed the ground and the knight turned his helmeted head to look down at Ron.
"Do we— er— have to join you to get across?" The black knight nodded. Ron turned to the other three. "This needs thinking about..." he said. "I suppose we've got to take the place of four of the black pieces..."
Harry and Hermione stayed quiet, watching Ron think. (Y/n) looked at the board.

"Definitely a challenge from Professor McGonagall," (Y/n) said. "She's good. Really good at chess." Ron looked at her calculatedly.

"Now, don't be offended or anything," he told Harry and Hermione, "but neither of you are that good at chess—"

"We're not offended," said Harry quickly. "Just tell us what to do."

"Well, Harry, you take the place of that bishop, and Hermione, you go there instead of that castle."

"What about you and (Y/n)?"

"I'm going to be the knight," said Ron. He hesitated when it came to (Y/n). Neither of them could play the same piece out of his fear of having to sacrifice one of them (other than a pawn). "And (Y/n)... she'll be the Queen. I trust her enough for that." (Y/n) grimaced.

The chessmen seemed to have been listening, because at these words, a knight, a bishop, and a castle turned their backs on the white pieces and walked off the board, leaving three empty squares that Harry, Ron, and Hermine took. The Queen stepped off of her pedestal and bowed before (Y/n) giving her a crown.

"What the—" (Y/n) muttered.

"Take it!" the three shouted. (Y/n) reluctantly took it, placing the too-large crown on her head.

"White always plays first in chess," said Ron, peering across the board. "Yes... look..."
A white pawn had moved forward two squares.
on started to direct the black pieces. They moved silently wherever he sent them. Harry's knees were trembling. What if they lost?
"Harry— move diagonally four squares to the right."
Their first real shock came when their other knight was taken. The white queen smashed him to the floor and dragged him off the board, where he lay quite still, face down.
"Had to let that happen," said Ron, looking shaken. "Leave you free to take that bishop, Hermione, go on."
Every time one of their men was lost, the white pieces showed no mercy. Soon there was a huddle of limp black players slumped along the way. Twice, Ron only just noticed in time that Harry and Hermione were in danger. He had (Y/n) moving all around the board, protecting both Hermione and Harry along with their King, taking pieces, and still keeping her safe. 
"We're nearly there," he muttered suddenly. "Let me think— let me think..."
The white queen turned her blank face toward him.
"Yes..." Ron said softly, "it's the only way... I've got to be taken."

"NO!" the three others shouted.

"That's chess!" Ron snapped. "You've got to make some sacrifices! I'll make my move and she'll take me— that leaves you free to checkmate the king, Harry!"