In a spoiler-soaked preview of the final season, Kevin McFarland looks at one character's embrace of humility led him to Heisenberg, protagonist Walter White's menacing alter-ego of in the world of Breaking Bad. Contains spoilers for episodes leading up to, but not including, the final eight of Season 5.

The final moment of last year's Breaking Bad midseason finale shows Hank Schrader's great epiphany. On the toilet, Hank looks directly behind him for reading material, and happens upon a copy of Walt Whitman's Leaves Of Grass — gifted to Walt by Gale Boetticher, one of the many pseudo-innocents left in a bloody wake as Walt ascends to control meth production. Hank flips the pages, and discovers a curious personal message that unlocks the answer to the riddle he's been toying with for five seasons.

But to get to that point, Walt and Hank had to rise and fall respectively, to where their professional lives outside family connection could converge. Creator Vince Gilligan will be the first to point out that his writing staff, cast, and crew deserves most of the credit for the expansion and progression of Breaking Bad. And one of the clearest examples of how his original vision of the character dynamics shifted through the series is the relationship between Walt and Hank. 

In the pilot–the one episode Gilligan wrote without any other input, and the initial conception of the Breaking Bad world–Hank is the inverse of everything Walt stands for before his cancer diagnosis.

Hank is macho, boisterous, tough, and engaged in dangerous activity. He shows off his gun, emphasizing how uncomfortable it looks in Walt's hand. He soaks up the admiration from Walt's son, the classical male ideal taking father-figure precedence over a scientist-turned-schoolteacher. Hank even usurps Walt's 50th birthday party and takes the poor guy's own beer when making a toast. Over the course of the first season, Hank is everything Walt is not, the dominant alpha over Walt's passivity. Hank confronts Walt about missing chemistry lab equipment from the high school–but laughs at the possibility of someone like Walt being the man behind the mythic Heisenberg. Hank's belief in Walt's beta-male stature makes it easier for Walt to hide in that blind spot.

But credit the actor behind Hank, Dean Norris, and the rest of the show's staff for fleshing this character out. His outer rock-solid machismo is just a veneer, hiding a fearful, nervous man who questions whether he should continue to doggedly chase promotions at the DEA. When he lucks into finding Tuco Salamanca in the desert–unknowingly rescuing Walt and Jesse in the process–he snaps into action and kills Tuco in the field. His reaction to all the praise he receives hints at his agitated mindset. He has a panic attack in an elevator when promoted to work in the El Paso office, then physically recoils at the sight of an informant's severed head on a tortoise (which probably saves his life). At increasingly dangerous turns, Hank jettisons the loud, insensitive work personality, revealing more of himself as a flawed man.

Failure in El Paso–and here failure is defined by fear, queasiness, and a desire for a quiet lifestyle in Albuquerque–begins the road down from a showy, boastful place. His wife Marie dreamed of a little Georgetown apartment after Hank's continued rise through the DEA ranks on the way to DC. But in order to reach the point where luck could intervene to gift Hank the missed connection to the real Heisenberg, he must first go through a classical fall from grace.

Third season episode "One Minute" is perhaps the defining crucible moment for the character. After Walt and Jesse end up just within Hank's reach, with the pair trapped inside the RV in Old Joe's junkyard, Walt's desperate ploy to make Hank think his wife was rushed to the hospital enables their escape. But that cruel trick triggers the last gasp of Hank's volatility: he violently beats Jesse in revenge and places his own professional future in jeopardy. In the elevator with Marie at the DEA after giving his statement, Hank breaks down sobbing, mentally at his lowest point, the polar opposite of his dominant male persona. Meanwhile, unbeknownst to Hank, Gus Fring sends the Salamanca cousins after him –leading to the titular shootout, a breathtakingly tense sequence that couples mental failure to a physical crippling.

"What I did to Pinkman…that's not who I'm supposed to be."

In the aftermath of "One Minute," Hank is dejected. He is disinterested in his work, his family, and his life. But what gets him back on track is the continued pursuit of Heisenberg. Hank realizes his skills as a tinkerer, a detective, more than his impression of a rough-and-tumble DEA super agent. He searches for connections and over. He analyzes every seemingly insignificant detail, trusting his instincts to continue what everyone else views as an obsessive, fruitless investigation. After Gustavo Fring's violent demise in Hector Salamanca's nursing home and the explosion, he gets major credit, but even then is advised that the Heisenberg case is closed.

Walt's diagnosis awoke a dormant ambition which has been within him since he was a brilliant graduate student. That internal drive led him to pushing Jesse to expand their business and reach far beyond their grasp. It led to Saul Goodman, to Gustavo Fring, to Madrigal Electromotive. That zeal led Walt to a kind of anonymous infamy which still eats at him, as he foolishly ascends to Ozymandias levels of hubris–but Hank's refocus and lowered expectations kept him in Walt's path.

After the horrific and visually stunning sequence that eradicates the 10 men desperate to make DEA deals, Hank is beside himself again, wondering aloud to Walt whether his first backbreaking outdoor job was preferable to "hunting monsters." Walt hungered for more and more control, taking larger slices of the pie until Skyler unveiled an unfathomable treasure trove tucked away in a nondescript storage unit.

Those opposing trajectories form Breaking Bad's examination of masculinity, which is one of many thematic threads throughout the series. Hank's slow acceptance of his place in law enforcement, his limitations and strengths as an investigator, combined with Walt's cancerous arrogance, allowed for Hank's toilet epiphany. Two brothers-in-law, a stereotypical macho man and a seemingly passive man beaten down by life, were transformed. Walt found the terrifying glee of power, and Hank found the freedom of humility.

The final eight episodes will bring these threads to their ultimate conclusion, reconciling Walt's relationships to his estranged co-conspirator wife, his innocent son, and Jesse–a surrogate child, colleague, and friend, all rolled into one person. But without Hank's chiral progression, echoing Walt's chemistry lectures from the early episodes, the DEA agent would never have ended up in the position he was in the final scene of Season 5, episode 8. Only after this internal transformation could Hank find himself in that most humble but lucky spot — on the toilet — reaching into his literal blind spot to discover the one piece of evidence he needed to make the sprawling Heisenberg case click into place.