Walter White spends much of "Blood Money" — the terrific, riveting premiere that kicks off Breaking Bad's final eight episodes — pretending that he's changed. Early in the episode, he describes himself as a "successful car wash owner." He relaxes at a barbecue. He plans a romantic trip to Europe with Skyler. He works behind the same car wash counter where he began the series, obsessing over the placement of air fresheners.

Of course, this being television — and Breaking Bad being Breaking Bad — it isn't as easy as all that.

"Son, you need to stop focusing on the darkness behind you. The past is the past," Walt tells Jesse. "Nothing can change what we've done, but now, that's over. You're out, and so am I." But bells can't be unrung, Pandora's Box can't be closed again, and you can't simply go from "I am the one who knocks" to "Have an A-1 day." Breaking Bad is a morality play, and we're in the inevitably tragic final act. We even have a hint of where it's going, as the episode opens with a stunning flash-forward: The White home, torn up and sealed off by the DEA, with "Heisenberg" spray-painted in large letters across the living room.

As Breaking Bad heavily telegraphed last year, Walter's cancer is back — and was probably part of the reason he agreed to retire from his so-called meth empire in the first place. Walter is, quite literally, at the end of his arc, both as a character and a human being; I suspect that his long hair in the flash-forward sequence serves as both a disguise and proof positive that he's given up on chemotherapy and accepted his impending death.

But while Walter's story is reaching the only ending it could ever have had, the people around him have plenty left to do — and plenty left to lose. Maybe that's why I keep returning to Hank, who, having finally uncovered Walter's secret, has been propelled into a new arc of his own. Until now, I had only thought about the ending of last year's midseason finale, which saw Hank finally discovering Walter's secret, from a pragmatic perspective: How would Hank react, and what would that ultimately mean for Walter and Skyler? But "Blood Money" focuses first on the emotional impact on Hank, and it's some of Dean Norris' finest work to date. The raw shock of the revelation propels him into a panic attack, which he overcomes by obsessively focusing on a new mission: Gathering the evidence and taking Walter down.

In many ways, Hank's sudden discovery has turned him into a Bizarro version of Walter White: He's lying to his wife and shirking his normal responsibilities at work. (The fantastic montage in which Hank reassembles all the evidence from the Heisenberg case files even plays out like one of Breaking Bad's patented meth-cooking montages.) In an alternate universe, Breaking Bad could just as easily have been a more conventional show about a DEA agent who eventually discovers that his meek brother-in-law has been a criminal all along.

It's to Breaking Bad's great credit that the show doesn't cheat the intelligence of either Walter or Hank for the sake of drawing out the suspense a little longer. A lesser show would have done everything possible to drag this cat-and-mouse game out over an entire season, but Breaking Bad has always played fair: Within three days of realizing that Walter is the "W.W." referenced by Gale in his lab book, Hank has amassed a formidable stack of evidence against him.

But as always, Walter is no slouch, either. The moment he realizes his copy of Leaves of Grass has disappeared, he figures out what has probably happened — and in the very same evening, he uncovers a GPS tracking device on the bottom of his car that confirms his suspicions.

In the riveting final sequence, Cranston and Norris manage to play every layer of what's going on: The surface conversation straining to be friendly, and the barely suppressed hurt and rage underneath as they each attempt to tease out how much the other one really knows.

It's when Walt plays his trump card — the GPS tracker — that Hank closes the garage door and lets the real conversation begin, rattling off a damning rap sheet of Walter's crimes. "It was you all along. It was you. You son of a bitch. You drove into traffic to keep me from that laundry. That call I got telling me Marie was in the hospital. You killed ten witnesses to save your sorry ass. You bombed a nursing home. Heisenberg. Heisenberg."

As usual, Walter tries every tactic to placate him, but Hank — morally upright as always — can't be moved. Hank is the second of Walter's former loved ones to tell him they hope his cancer kills him, and he spits it out like a viper: "Rot, you son of a bitch." In response, Walter makes an emotional plea that's a version of the same argument he made to Jesse earlier in the episode: "I'm a dying man who runs a car wash. My right hand of god, that's all I am." He says it so pathetically that it's hard, briefly, not to feel pity for him.

By the end of the episode, Walter has reverted back to Heisenberg mode. But even if he hadn't, even if Walter was committed to spending the rest of his life breaking good, he can't account for the bodies he's left in his wake. When Walter tells Jesse that the "past is past," he's trying to get him to move on: If you can't change the past, why let it bother you? He fails to recognize the darker truth that Jesse sees lurking behind that idea: If you can't change the past, you can never do anything to fix it.

We already know the end of this story — or, at the very least, the beginning of the end. Walter is too far into the tailspin to pull himself out now; neither his allies, like Lydia, nor his enemies, like Hank, will let him.

The flash-forward that opens "Blood Money" gets right to the heart of the show's central theme. There's been an inevitability to Breaking Bad from the very beginning. Walter White's personal philosophy may hinge on the idea that he's in control of his life, but he's still subject to the forces outside his control: A plane collision over his neighborhood, or a series of bank account numbers that the police can use to track the bank accounts of Gus Fring's accomplices. ("Blood Money" even doubles down on the Godfather references that peppered last year's midseason finale, as Walter's neighbor Carol drops a bag of oranges — a symbol of impending death in the Godfather franchise.)

As always, Breaking Bad operates on the principles of science, and everything the show has shown us so far has been a kind of lab experiment: How far into the dark side can one man go — and how much can he do before he'll be punished for it? As the final run of episodes begins, we're finally at the end of that journey — and it already looks like we're at the moment when everything's about to explode.

Still in a Breaking Bad mood? Read The Week's predictions for the rest of the season, or watch the 13 funniest Breaking Bad parodies.