I was completely lost. Who is Nathan, who is the Boston girl and why are they running for their lives? Am I supposed to know or am I just clueless?

@ smsdasilva: Well maybe… you could write a prequel to it! ;)

It does want a prequel; but part of its call is the slightly unknown quality. It almost leads the mind to make a subjective interpretation, like song lyrics (well, some song lyrics.)