He's a Tough One

"What are you looking at? Focus on eating," Chen said to Ai Haibara.

"I feel like there's something off about that old lady," Ai Haibara said quietly.

"Whether something's off or not has nothing to do with us. Hurry up and eat."

"Grandmother's always been like this. She still thinks my mother is alive," Takamasa said, shaking his head.

"No wonder her memory is poor. Ever since her legs started hurting years ago, she's been stuck in this castle and hasn't gone outside!"

"By the way, have you solved the riddle, Professor Agasa?" Master Aman asked Professor Agasa.

"Ah?" Professor Agasa was clearly taken aback.

"Haven't you heard? Before my father-in-law died, he said that whoever could solve the mystery of this castle would receive his most precious treasure."

"Ah, I've heard about that, but I don't know where to begin looking." Professor Agasa scratched his head.

"Start with the Western chess pieces arranged in the courtyard! Conan seemed to disappear after looking at those pieces," Chen suddenly said.

"If the chess pieces in the courtyard were arranged by the person who hid the treasure, then perhaps they can solve the riddle and lead us to it."

"Oh?" Master Aman and Takamasa exchanged a look.

"Could it be that you already know the true meaning of the pieces?" Takamasa asked Chen.

Chen took a sip of water and said blandly, "How would I know? You people spent four years without solving it."

"By the way, where exactly did that little boy with glasses go?" Aman asked.

"He disappeared earlier," Professor Agasa said, spreading his hands.

If anyone else had gone missing, Professor Agasa would certainly have been frantic. But since it was Conan, he was not quite so anxious.

"I think he probably got lost somewhere in the castle. There