"It has only the pictures, not the words," Hiro says to Ando about Isaac's unfinished comic book at the beginning of "The Hard Part," and that's a good description of just what the heroes are dealing with as they try to stop New York City from exploding.
Who is the exploding man?
Ted is the original source of the nuclear power, and he has arrived in New York. However, Peter has absorbed it, and Sylar can acquire it by taking Ted's brain. When we add in the fact that Candice can make anyone see anything she pleases, and Peter and Sylar can each get her power in their particular ways, we have a story in which even pictures are not reliable. We certainly have no idea what the picture in the comic is thinking or saying. Pictures with no words. Scenes that show what's happening but are almost blank slates for the viewers. It is a semiotician's sweet dream.
Seeing the future has always been a risky business – just ask Hari Seldon in Asimov's Foundation series or Paul Muad'dib in Frank Herbert's Dune. The harder you work to prevent something bad from happening, the more you risk being the one to make it happen. Heroes risked spinning out of control in the first third of this season, as heroes were introduced with new powers almost at the drop of a hat, but the convergence of everyone in New York City is giving the series a satisfying, irresistible focus and intensity.
We are beginning to see the components of the final picture. Now all we need are how they fit together, and the words.