If you are completely averse to spoilers, you might think twice about reading this.  It deals with some points that we should be learning more about next week.

We open in a devastated New York, five years in the future.  Hiro is battling what appears to be police officers, and his internal dialogue tells us that he is trying to save one of his own.  Having finally gotten rid of them, he tells the girl he was defending, ‘Sparrow’, that the curfew is on and she needs to get off of the streets.  This jives with rumors we’ve heard that in the future, our heroes are hunted, specifically, after the blast. 

Hiro returns to his hideout, which is Isaac’s old apartment.  He has to change what happened.  We come to find out that, after having five years to manipulate time, he has come to understand it.  He has found that time is not a straight line, but rather the interconnection of multiple lines, hence, the strings last night in future Isaac’s apartment, and the name, String Theory. 

We begin to get an idea of what happened when the bomb went off.  Sylar was the bomb, and Hiro tried to stab him, but he still detonated.  Sylar was able to regenerate, though, because he had killed Claire and stolen her healing power.  Hiro makes his decision that, if he can keep Claire from being killed, he can stop the bomb.  So he travels back…meets Peter…thus, “Save the cheerleader, save the world.”

Upon returning from the past, he finds that New York has still been ravaged by the bomb.  Confused, he returns to his apartment, and meets his past self in the final scene of last night’s episode.

These issues have been getting better and better, I think, and this one definitely continues the trend.  We get some good flashbackiness and some good setup for next week’s episode, also called String Theory.