The last two seasons haven't exactly been memorable for "Heroes." But NBC, now under new management, wants to show that not only is Hiro, Sylar, Matt Parkman and the Petrellis are back, but so is the quality.

That's why the first line you hear in the latest commercial for "Heroes" is that the show is "back at its best."

But is it? There are a lot of questions surrounding "Heroes," especially with some thoughts that the show is a one-season wonder and has now overstayed its welcome.

The show will get one last chance to either shine or fade, and the network has promised to pull out all stops to make it happen.

"Heroes" returns to NBC Sept. 21.