Quotes of the Day

In this insecure economy, you may be suffering on-the-job stress. But if your boss is not trying to have you killed, you're one up on Walter White.

At the end of Breaking Bad's third season, Walt (Bryan Cranston), a high school chemistry teacher turned crystal-meth maker, fell out with his boss, Gus Fring (Giancarlo Esposito). So Gus put out a hit on him and his partner, Jesse Pinkman (Aaron Paul). As Season 4 begins (July 17 on AMC), Walt has survived, but his professional situation is, shall we say, tense. In a scene shooting on Breaking Bad's Albuquerque, N.M., set, Walt's estranged wife Skyler (Anna Gunn) asks him if he's in danger. He's insulted; in his mind, he's a player in the drug world, as big a threat as anyone. "Who are you talking to right now?" he demands. "Who is it that you think you see?"

That is the question. When the world looks at Walt, it sees a tired, unemployed, middle-aged man. Breaking Bad viewers see a man who has made millions in the drug business, killed rivals and dissolved their bodies in acid. He is a pawn, and he is a kingpin. He is a nebbish, and he is a murderer. To paraphrase a quote that creator Vince Gilligan uses to sum up his show, he is Mr. Chips, and he is Scarface.

The true identity of Walter White is Breaking Bad's philosophical long game. Is he a good man who turned bad? Has he always been bad? What keeps any of us from doing evil besides need and opportunity? It is this kind of investigation that makes Breaking Bad TV's reigning best drama and, despite its premise, its most intensely moral one.

When Breaking Bad debuted in 2008, it seemed like a dark comedy along the lines of Showtime's suburban pot-dealing show Weeds. Walt, a chemistry genius whose career fizzled out, is teaching kids he resents and working part time at a car wash — then he gets diagnosed with lung cancer. Desperate to build a nest egg for his family before he dies, he partners with Jesse, his former student and a small-time dealer, to cook meth. It turns out he's amazing at it. And it feels good. He stays in the business even after his cancer goes into remission. "He wants to own this," says Cranston, who's won three Emmys for the role. "He's feeling powerful for the first time in his life." As Walt gets in deeper, embracing his criminality and signing on to run Gus' pharmaceutical-grade-meth superlab, Breaking Bad becomes something incredibly compelling — and dead serious.

This evolution, says Gilligan, a former X-Files producer, was by design. "In the early going, the audience understands the absurdity of the whole situation — a middle-aged man willing himself to become a drug king," he says. "As he succeeds, organically the story must become darker, unless you want to do the Hogan's Heroes version of being a meth cook."

Breaking Bad is the kind of TV show that gets described as cinematic, and that's true in the literal sense: it looks like a movie. The astonishing landscape of New Mexico gives the show a western-film starkness and scale. "When you're here," says cinematographer Michael Slovis, "you can't help but be affected by the size of the sky." The sets are painstakingly built, especially the superlab: a temple of gleaming metal tanks, painted infernal red, that production designer Mark Freeborn built with the aid of a Drug Enforcement Administration consultant. The lab, Cranston says, is a metaphor for Walt's compartmentalized worldview: "It's clean. It's isolated. He doesn't like being reminded that he's part of a messy, bloody business."

But one trick to doing a cinematic TV series right is to understand that TV is not the movies. The films that Breaking Bad recalls — Sergio Leone's westerns, No Country for Old Men — work with big events, big images and grand themes. Great TV can do that. But series TV also works on a more intimate level. Breaking Bad is the story of not just Walter White, criminal, but also Walter White, husband and dad. That's what gives the show its disturbing force. You could hold Tony Soprano at arm's length; he was born into a criminal world alien to most of us. Walt, a hunched suburbanite who drives a Pontiac Aztek, chose his life. There but for an unimpressive high school chemistry record go I?

This story called for a star who could convincingly play explosive moments and minutiae. Cranston surprised viewers who knew him as Hal, the pratfall-prone dad from Malcolm in the Middle. But Gilligan had cast him years before as an X-Files villain. "I first knew him as a badass," Gilligan says. "When Malcolm came on the air, I did a double take: My God, that's Bryan Cranston?"

Between scenes, Cranston is in his trailer getting into character, which means shaving his head. Walt lost his hair to chemotherapy, then chose to stay bald. Cranston, who has immersively worked on Walt's backstory, says the severe coiffure does more than look fierce; it also offers psychological camouflage. "This is a specific look he wants," Cranston says. "As long as he doesn't recognize this guy, he can justify his actions. This is a different guy."

Walt has always been balanced by Jesse, but their odd-couple dynamic has changed. When the series began, Jesse was the punk and Walt the straight man, Jesse the nitwit and Walt the teacher. Over time, other differences have emerged. Jesse is more willing to act on feelings of passion and injustice, whereas Walt acts on cold self-interest. In his own feral, meth-head way, Jesse is the show's conscience. Though he was Walt's entrée into the drug world, we see that's he's really just a kid, not suited to the depths of corruption Walt drags him into. "There is this loss of innocence," says Paul, who won a supporting-actor Emmy last year for the role. "Yeah, Jesse cooks drugs, and it's horrible for society, but he has a good heart."

Season 3 ended with Jesse preparing to cross the moral point of no return, as Walt asked him to kill an innocent man in order to save their own lives. I won't say how Season 4 resolves that cliff-hanger, but the first episode plays out the consequences with taut and patient suspense. One thing is clear: Walt and Jesse can't go on like this endlessly.

Nor does Gilligan want them to. The creator says he has the broad outlines of a Season 5 in mind, but he hopes to set an end date. Most TV shows are about stasis — restoring the status quo over and over — but in the pilot of Breaking Bad, Walt makes a comment about his field that could be a motto for the series itself: chemistry "is about change ... growth, then decay, then transformation." Says Gilligan: "There's no reason a show like ER or Law & Order theoretically can't go on forever. But a show like this is designed to end." As all good experiments must.

• James Poniewozik / Albuquerque