The Spelunker finds the book when he first enters the Entrance Cave and discovers it belonged to Yang. He reads about Yang's journey, which begins the interactive tutorial for the player as they take control of Yang for the duration of the three training levels. After completing the tutorial, the Spelunker finds a key tucked into the last page and uses it to open the entrance to the Mines, beginning their own adventure. During the game, the journal will automatically document all the places you visit, the monsters you kill (or are killed by), the items you find and the traps you fall victim to.