This question is in relation to the story about detectives Sancho and Bolsa trying to find a man named William Morningstar.
William was not owed money by Billy Jo but William apparently owed Billy Joe some money. This was why Billy Jo hired Sancho and Bolsa to find William in the first place as it was thought that William was hiding so as to raise the money he owed Billy Jo.
I am very proud that you're going to study an exchange program to study Spanish! Remember to stay safe and don't stay out till night. Always have a small weapon for your safety. Don't focus on relationships and study hard so that we can travel together one day.