2 What was that?

I have no idea what I just read, to be honest. If someone asked me to give a short summary of this book, I wouldn't be able to give even one sentence.
There are multiple stories within this novel: one takes place in just one night, starts with an American named Sean shooting one of the big mafia bosses in Manila and his bodyguard. Sean is then being chased by two other bodyguards, ends up holding a young mother of two, Rosa, hostage, and all that is being witnessed by two street kids, Vincente (Cento) and Totoy.
The other story lines take us back to Rosa's childhood and her first love, to Vincente's past and how he became a street kid, with no family.
There are things in this novel that are still confusing the crap out of me, even after reading it. I also don't really understand the role of Alfredo, a PhD student, a very rich PhD student, who is collecting the dreams of street kids in order to write his dissertation. If the author wasn't really going to provide us background of Alfredo and his wife, why put them in the book in the first place?