"Tyakhtiymantteli: The Collection" is a novel by the Finnish writer Yoel Lehtonen, which tells the story of the mysterious world and the adventures of the main character Juhann. He finds himself in the fantastic world of Tjahtijmanttel, where he encounters incredible characters, magical places and dangers. This book is full of magic, mystery and adventure that will take the reader into an exciting world of fantasy and adventure.