The extras and episodes are spread across four discs, with audio commentaries on all episodes by a variety of cast and crew. Not everyone appears on every commentary -- you’ll get a cast member and a producer on one episode, then a different cast member and a different production person on another. They’re delightful folks who clearly love their work and can be very funny talking about it -- Greg Grunberg (“Matt Parkman”) is particularly and appealingly enthusiastic -- but don’t expect the kind of snarking that we might have had if a few more years had passed before the commentaries were recorded and subsequent seasons had proven the show able to bounce back. It’s charming to hear Masi Oka (“Hiro Nakamura”) call Claire Bennet Heroes’ “Kenny from South Park” because she’s constantly dying and resurrecting herself, as he does on his commentary on Chapter Seven: “Out of Time,” but when he lets us know that if we thought the episodes up to this one were a little slow, we should hang on because it’s gonna pick up after this, there’s a sense of PR-speak about that where previously he’d sounded so genuine. No one is listening to the commentaries who hasn’t already formed their opinion about how the season wraps up. I would much rather have heard him voice a little bit of dissatisfaction with how ridiculously Hiro’s sojourn in medieval Japan was dragged out. Oka may have enjoyed working, as an actor, in that milieu, but as a fan, as he proclaims himself to be, he has to have seen that a good concept was taken well past its sell-by date.

But there’s that subtext I was talking about. Oka’s reference to any frustration with the show springs from what fans and critics like me were harping on over the course of the season, which producer Tim Kring responded to as the season was still airing... and, indeed, as it was still in production. It’s hard to see that the change in tone that the last third of these 11 episodes saw isn’t a reaction to the fans’ grumbling... as much as it was also a reaction to the looming writers strike. On Disc 4 there’s an “alternate ending” for the season that posits that Adam (aka “Takezo Kensei”) in fact dropped the vial of virus, and that the virus escaped and become airborne. Events play out very differently after that: the near future that Peter visited, in which the human population has been driven almost to extinction, The Stand-style, comes to pass. Indeed, it felt at the time like a huge cheat that that future was avoided, and in the about-the-alternate-ending featurette, Kring explains how the then-potential writers’ strike forced the producers to consider whether they wanted to end on a cliffhanger -- of the virus having gotten loose -- if they might be off the air for an extended period of time. But “the entire season hinged around” this idea of the viral outbreak, Kring says, and to abandon it so suddenly feels cheap, and I wonder how much of it had to do with the impending strike and how much came out of a desire to wrap up a storyline that the producers knew the fans were not enjoying. How they did it leaves a lot to be desired, and whether we can forgive them will depend on how well the show comes back in Season Three.

And speaking of Season Three -- which debuts on September 22 with a two-hour, two-episode premiere -- Disc 4 also contains a sneak peek at the upcoming stories. The season will open by picking up right where it left off, with Nathan’s apparent assassination, and if you freeze-frame on one shot of a script for the season opening, you can discover who shot Nathan. (I won’t spoil it for you, but click here if you want to see a screengrab of the shot. Don’t come bitching to me if you didn’t want to have the surprise ruined for you.) Jack Coleman (“Noah Bennet”/“Horn Rimmed Guy”) appears to have been the designated spokesman for the new season; he says here: “You’re gonna see villains that you know and some that you don’t know, some people that you think have been good... There’s gonna be some time travel, there’s gonna be some alliances you’d never expect.” But then, he has to say that, doesn’t he?

There’s also bonus material that’s just plain cool and uber-geeky. On Disc 2 there’s the multi-part mockumentary “Takezo Kensei: Sword Saint,” which plays like something you’d see on PBS and is “made possible by a grant from The Yamagato Fellowship.” (There’s a whole online viral thing connected to the fellowship, if you need to waste some more time on this fictional universe.) Also on Disc 2 is “The Drucker Files,” from “Global News Interactive” on the mysterious and reclusive Richard Drucker, “the godfather of the Internet” and a character from the supplementary online graphic novels. I wonder if the inclusion of this material is a kind of sneaky Season Three easter egg: Will Drucker figure in the new storyline?

On Disc 3 is the featurette “Genetics of a Scene,” which covers how the show re-created medieval Japan and South America in Southern California, made Nathan and Peter fly over New York City, and more. It’s juicy stuff for production geeks. The deleted scenes -- spread across Discs 1 through 3 -- are fun, too, and give us some insight into the powers of the older generation, what Nathan Petrelli feels about his family, Suresh being evil, a surprise use for West’s flying talent, Molly’s feelings about using her powers to play hide-and-seek, and more.

Funniest thing about the whole set: hearing everyone talk in their native accents. There’s a startling number of put-on accents on the show, but hands-down, you’ll be most astonished by Sendhil Ramamurthy, who plays Mohinder, and his totally flat Midwestern American accent. I knew he didn’t really speak with an English -- or pseudo-English Anglo-Indian -- accent, but hearing him yak like a Yank is kind of staggering.