Bia's antics - The old leather book

With this book, Bia first learned about her parent's history. 

She would spend  hours in the afternoon  lying on the wooden floor of her room on the boat just reading the book.

It was a huge book made entirely of dark leather. There was nothing on the cover, just the leather, so that a thief would not think it was valuable. But if you dared to open the book the first words you would read were "treasure book". 

The first time Bia opened the book she did not know what treasure means so she did not got from the first page before letting the book aside and going back to play. 

The second time she opened the book, it was just because she was very bored. But as she already knew what a treasure was, it had become the most interesting book she ever read.

The first page contained a list of rules

Bia already knew even before she could read.

Before I said what they are, there is this interesting story about it:

When B