But if the story line propels me into my TV grotto, it’s the realism that keeps me there. There’s nothing artificial about “Breaking Bad” — the spell is never broken. The dialogue is pitch-perfect. And there’s a lot of useless but fascinating information: you can learn how a meth lab operates, how money is laundered and guns are sold, how to murder people. (This is not necessarily a good thing. Dzhokhar Tsarnaev, accused in the Boston Marathon bombings, tweeted: “ ‘Breaking Bad’ taught me how to dispose of a corpse.”) And if you want to know how crack is smoked, how a heroin needle is inserted, the spoon heated up, I highly recommend this show. Self-destruction is interesting.

THEN there’s the background, the territory. We know our way around Faulkner’s Yoknapatawpha, Joyce’s Dublin and Bellow’s Chicago: now we have the Albuquerque of “Breaking Bad.” It’s a second home to me: I know its restaurants, its scrubby desert, its ranch houses with their two-car garages and swimming pools. The characters become weirdly familiar, too. I spend more time in their company than I do with my closest friends. I observe them closely. There comes a point when these are no longer actors to me: they are real people leading their lives. I spot a familiar face on the red carpet at the Academy Awards and exclaim, “That’s Walt!” It turns out to be someone named Bryan Cranston.

The most compelling thing about the show, though, what makes it unique among TV series, is its depiction of how good and evil can coexist in one person. Walt gets into the meth business for an altruistic reason: he has lung cancer and wants to ensure his family’s financial security after he dies. Walt is a decent man. He cares for his teenage son, who has cerebral palsy; he feeds the baby. He’s monogamous even when he’s separated from his wife, Skyler. He’s a moralist: “It’s about choices, choices that I have made, choices I stand by.” And his knowledge of chemistry, displayed at odd moments, makes him endearing. (The show was pitched as “Mr. Chips” becomes “Scarface.”)

But he grows comfortable in the bad-guy role and soon discovers that he’s capable of getting rid of his enemies without compunction and in the most gruesome ways. “I am not in danger,” he says to Skyler at one terrifying juncture in their descent. “I am the danger.” Where he once had trouble loading and drawing a gun, by the end of Season 4 he’s able to blow up an old man in a nursing home.

The corruption of character doesn’t happen overnight. Its progress is insidious. Most of the characters in “Breaking Bad” are not all bad; even Mike, the resident hit man, can hand his granddaughter a bouquet of balloons before heading off to put a bullet in someone’s head. Like the characters in Dostoyevsky, Camus and Céline, Walt inhabits a world of moral ambiguity that TV has never been given the time to explore in depth until now. I watch “Breaking Bad” for the same reason I read the classics: to discover why people act the way they do. (Also, it’s colossally entertaining.)

So it turns out you can buy the first half of Season 5 on iTunes. There goes the week. At this rate, I’ll never get through “War and Peace.”