Once upon a time, in a peaceful mountain village, the quiet night was filled with whispers. A precious old manuscript, the town's pride, had been taken from the library. Everyone was in shock and didn't know what to do. But young detective Luca, with his love for puzzles, was excited to solve this mystery. He grabbed his magnifying glass and notepad, ready to start his voyage of discovery.

Luca first visited Mr. Biblio, the wacky librarian with big glasses and a love for stories. Mr. Biblio was sad about the lost book but didn't know who could have taken it. Luca noted how Mr. Biblio's eyes got wide when talking about the old manuscript, making a little note on his pad.

Next, Luca met a tourist lady with a big hat. She traveled the world to read old books. She seemed very clever and knew a lot about the missing manuscript. The lady smiled warmly at Luca but he wondered if she smiled to hide a secret.

On the third day, Luca spotted a curious figure lurking near the library. It was a man in a long coat, who looked around a lot. Luca sneakily followed the man and discovered he had a hidden pocket inside his coat. Was this a clue, or just a trick?

Luca gathered all the people together in the library. He had many pieces of a puzzle but needed to find out how they fit. The librarian, the tourist, and the man in the coat all stood nervously as Luca looked at his notes.

With a big smile, Luca announced he had found where the book was hidden! Inside a secret room behind the library, there stood the old manuscript! It was Mr. Biblio who hid the book because he was afraid someone would take it and not treat it with care.

Everybody cheered for Luca, and Mr. Biblio promised to make a special glass case to keep the book safe but also let everyone see it. Luca felt happy he had helped his village and solved the big puzzle. And with that, the village went back to being peaceful, knowing Luca was there to solve any mystery.