A Clue to the Secret Book

I heard Mr. Wetbottom in map is going through hard times... I should go check on him.

At the VIP sauna in map, I met this bald man called Mr. Wetbottom. He has a son, and apparently he ran away from home one day with a book that he cares deeply for. He requested that I find his son and get the book back from him. For a reward, he's offering me a nice sauna robe. He also told me his son Ronnie hangs out at a tree tunnel around map, so maybe I can find him there. Anyway, is that book more important to him than his son?? What kind of a book is it anyway...????

I found Ronnie in the tree tunnel of map, as requested by Mr. Wetbottom, whom I met at the map.