“I am the one who knocks.” -WW

Poison figures prominently this season. Poison is how these people choose to kill because it’s underhanded, precise and can be done with a smile. Poison has to be administered by someone close, someone who appears to be an ally. But it’s not just literal poison; Walt is a poison, too. He’s toxic to everyone he touches.

Gus is not pleased with the murder of Gale, but can’t afford to stop production. To make sure Walt and Jesse know exactly what the stakes are, Gus slits his right hand man’s neck for not following protocol. It’s the first warning shot.

Walt and Jesse’s relationship is stretched to extreme limits this season. On one hand, they completely need one another to stay alive, but on the other hand they are both angry and isolated. Walt doesn’t like depending on Jesse – he becomes paranoid and suspicious of Jesse’s loyalty. Jealousy never works, so the more Walt tries to exert control and influence over Jesse, the more Jesse turns to Mike.

In Mike, Jesse starts to build the relationship he always wanted with Walt. Walt and Mike share a lot of traits – they are both family men, both used to be in a respectable profession (Mike was a cop), both seem to have no interest in the trappings of wealth and both see a picture bigger than the one directly in front of them. Mike easily taps into Jesse’s need for validation and comfort. Gale’s murder really, really messed with Jesse’s head, so he is ripe for the picking. When Jesse’s house becomes a drug den, it’s Mike who keeps an eye on him. Jesse is petulant and unappreciative, but Mike and Gus see what a steadfast ally Jesse will be if they can pry him from Walt.

Walt wants to be Gus: cunning, fastidious and in control. Like Walt’s relationship with Grey Matter, Gus has the albatross of the cartel around his neck. His business with the cartel is highly personal and it seems Gus has been waiting years to avenge a friend’s ruthless death.

Gus takes Jesse and Mike to Mexico, pretending to be there in peace and partnership, and in a bold move poisons the capo and his crew. During their escape, Gus is also overcome with poison and Mike is shot. Jesse is unharmed and the choice is his: leave them, kill them or save them. He saves them because between panic and instinct that’s who Jesse is – a saver.

Gus visits crazy Tio in the nursing home to gloat about his coup – it’s not like a man of Gus’s stature to brag about his accomplishments and it’s so out of turn with his discreet demeanor. Classic pride before the fall, even for the master.

Working on Gale’s murder case leads Hank to Los Pollos Hermanos, and he theorizes that Gale was Heisenberg. Walt’s ego can’t accept that, and he convinces Hank that the genius is still out there. As Hank rehabilitates his body, he zones in on the superlab. After questioning Gus about his connection to Gale, the DEA is satisfied with Gus’s incredibly logical and well-rehearsed answers. Only Hank is unmoved.

But as he dives into his work and his mineral collection (and a little soft porn), Hank retreats from Marie. She tries to support him and he’s downright mean to her. Poor Marie, her only source of comfort is crashing opening houses with a far-fetched story (“My husband is a retired astronaut”) and stealing trinkets.

While Walt and Skyler buy the car wash and flirt with reconciliation, it’s Skyler who bears the brunt of parenting. Walt Jr is still going hard on his mom, insisting that Walt’s gambling addiction is a sickness. On his 16th birthday, Walt Jr finds his father badly beaten (by Jesse), weepy and groggy. In an unsettling conversation the next day, Walt tells Junior not to think of him as weak after he’s gone. Junior senses there is a falsity to Walt’s character and he knows that in his dad’s drugged state he got a rare moment of genuine emotion.

Walt taps Jesse to kill Gus with poison, but Jesse is hesitant and doesn’t do it. Walt accuses him of being disloyal, and they have a brutal fistfight. Walt tells Jesse he hopes that the Mexican cartel kills him when they discover that he can’t cook. But Walt has seriously underestimated Jesse (again): Jesse cooks a very high quality batch and is suddenly Gus’s golden boy. He’s now more valuable – and better liked –than Walt.

To add to Skyler’s mess of a life, she stupidly signed off on Ted Beneke’s bad accounting, and now the IRS is after almost $700K. When Skyler rigs a fake inheritance, he still doesn’t pay off his taxes, choosing instead to lease a new Mercedes and reopen his failing business. When Skyler admits to being behind the inheritance, Ted subtly asks for more money. Lucky for her, Ted is injured and the IRS bill is paid in full.

Worn down by the constant danger and deception, Skyler heads to Four Corners Monument, seemingly determined to start fresh. She flips the coin, which lands on Colorado. Twice. She uses her foot to drag it back to New Mexico. Skyler doesn’t want escape, she wants a return to normalcy.

Gus takes Walt to the desert and tells him in no uncertain terms: Go away or I will kill you and your entire family. Walt decides to disappear with his family, but when he goes to find his money, Skyler admits she gave most of it to Ted. Walt lets out a guttural, insane laugh. It’s the laugh of a man who knows he’s f-cked. There’s no magic disappearing act. The irony can’t be lost on someone as smart as Walt: all the money he made cooking has been used to cover up for his cooking. It’s like a hamster wheel that goes nowhere.

Walt is over the poison—now he wants fireworks. He taps into both Gus and Jesse’s Achilles heels to end the turmoil. Andrea’ (Jesse’s girlfriend) son Brock falls ill, and Jesse realizes his poison cigarette is missing. Jesse is frantic and immediately suspects Walt is involved but Walt pleads his case – it was Gus who wants to drive a wedge between them. Jesse agrees that Gus must be taken out. In a stroke of brilliance, Walt has Tio goad Gus into a face-to-face meeting. At the last moment, Gus realizes he has been tricked, and Tio’s wheelchair explodes. Gus, refined to the last second, walks out of the room, adjusts his tie and, blown to pieces, collapses. It’s fitting that the man who wore two masks (respectable business man/ruthless drug lord) would find his end as half a face.

Walt informs Jesse that Gus is gone, and Jesse tells Walt that in fact the child wasn’t poisoned, he accidentally ate some berries off a common plant, Lily of the Valley, and will survive. They shake hands, satisfied with the outcome, and destroy the superlab in a cathartic end to the Gus era. Final scene is in Walt’s backyard, where we saw him a few episodes earlier, spinning a revolver in contemplation. Inconspicuously planted in the garden: Lily of the Valley.

Season 5 starts July 15! I won’t make any predications because they are always wrong, which is another reason I love this show.

Attached - Aaron Paul at the Television Journalists Association Second Annual Critics' Choice Awards.