Following the purchase of the M60 (""), Walter White drives up to the White residence, which is now fenced-in and derelict. He grabs a tire iron from the trunk of his car and enters the house. Trash and graffiti are everywhere; a group of teenagers skateboard in the empty backyard pool. Something catches Walt's eye as he walks through the wrecked skeletal remains of his living room. It's a single word, spray-painted in giant yellow letters on the wall: "HEISENBERG." In the bedroom, he retrieves the vial of ricin from its hiding spot behind a wall outlet plate. After retrieving the ricin, Walt leaves the house. Back outside, his neighbor Carol catches sight of Walt. "Hello, Carol," he says cordially and she drops her groceries in shock.
Hank Schrader leaves the bathroom, shocked, after reading the inscription in Walt's copy of Leaves of Grass (""). He places the book inside Marie's bag on the counter, then he and Marie leave the party, as he complains to her that he isn't feeling well. On the drive home, Hank has a panic attack and drives onto the lawn of a nearby house. He falls out of the car and Marie yells for the homeowner to call an ambulance. Back from the ER, Hank assures Marie there is no need for him to see a doctor, and he makes her promise not to tell Skyler. He then retrieves the evidence portfolio of Gale Boetticher's murder and lays the evidence out on a table in his garage. Hank compares the note "To my other favorite W.W." in the first page of Leaves to the "Favorite W.W." intro in Gale's lab notes; his suspicions of Walt's involvement are confirmed when he can visually see that both are written in the same (Gale's) handwriting.
At the car wash Walter reminds Skyler that their "story" needs to come first. Along those lines, he suggests that they buy an additional car wash, which will speed up the money laundering process. Lydia arrives for a wash. She goes and complains that the quality of the meth being produced since Walt left the operation is only 68 percent, which is placing her in a precarious position. She wants him to return for at least a few days and improve the operation. Walter sternly insists that her problems are none of his concern any longer. Skyler walks in and notices that Lydia is there washing a rental car, so asks Walt who she is. After a thought he admits that Lydia is a "former business associate" interested in seeing him return, but reassures her he will not. Skyler follows Lydia outside and tells her to leave and never return. The following morning, Hank tells Marie he's not going into work. On her way out, Marie sees two men delivering boxes. Hank tells them to put them in the garage. They leave and Hank starts searching through files related to Blue Sky, Gustavo Fring, and Heisenberg.
Skinny Pete and Badger get high at Jesse Pinkman's house and discuss Star Trek at length. Badger explains his idea for a Star Trek episode that features Spock, Kirk, and Chekov in a blueberry pie eating contest. In the imaginary episode, Kirk "yorks" and gives up the game early in the contest. At this point in Badger's story, Jesse grows tired of their conversation and goes upstairs. Badger continues with the story and says that Spock, who is competitive and accustomed to winning games, gets rattled when it appears that Chekov is winning. In fact, Chekov is cheating by using a transporter gun, handled by Scotty, that beams the pie from his stomach into space before he gets too full. However, Scotty gets distracted when Uhura walks into the room with her "big pointies" and accidentally kills Chekov by beaming his guts into space, leaving Spock as the only remaining player and, presumably, winner of the game.
When he goes back downstairs, Jesse brings his giant bags of money to Saul Goodman's office. While sitting in the waiting room, he grows tired of waiting and lights up a joint. Upon seeing this, the receptionist moves him to the front of the line to see Saul. Jesse says each bag contains $2.5 million and he wants one to go to Mike Ehrmantraut's granddaughter Kaylee and the other to Drew Sharp's parents. Saul seems uncomfortable with the idea but Jesse is adamant. Jesse leaves and Saul calls Walter. Walter takes the call while taking a course of chemotherapy and tells him to hang on to the money, adding that "[he]'ll handle it.". Although hinted at before, it is now confirmed that his cancer has returned. ("")
Walter shows up at Jesse's door with the money and asks for an explanation. Jesse responds, "It's like you said, it's blood money." ("") Walter tells Jesse to stop focusing on the past. He tells Jesse that he's out of the drug business himself and says there's nothing for them to do but live good lives. A teary-eyed Jesse thinks Mike's granddaughter needs someone to look after her. Jesse thinks Mike is dead and that Walt knows more than he lets on about Mike's fate. Walter denies having anything to do with Mike's death and tries to assuage Jesse's suspicions, saying, "I need you to believe me."
Later, the Whites are eating dinner at home when Walt excuses himself from dinner and rushes to the bathroom to vomit. He inadvertently peers above the toilet and notices his copy of Leaves of Grass has gone missing. He continues to search for the book all about the house. He gets into bed and, suspicious of Hank's possible involvement in the disappearance of the book, asks Skyler what is wrong with Hank. She tells him Hank hasn't been to work all week. Even more suspicious, he sneaks outside in the middle of the night and checks the bottom of his car, finding as he'd feared, a tracking device. Meanwhile, a homeless man knocks on the window of Jesse's parked car at the Dog House, waking him up from a nap. The vagrant asks a rather worse for wear Jesse if he can spare some change and he gives him a large stack of cash. The man, though markedly reluctant and perturbed by this windfall, eventually accepts and Jesse drives off. We next see Jesse, all glassy eyed and deeply perturbed, driving through an impoverished neighbourhood frantically tossing wads of cash into random lawns, visibly desperate to be rid of it all.
The two cops who dropped off the files ask Hank if Steven Gomez should be worried. Hank assures them that he's fine. As they leave, Walter pulls into the driveway. Hank nervously clears some evidence files and photos from the table. Walter feigns normalcy and asks how Hank's feeling. He tells Hank to let him know if there's anything he can do and walks away. Half way out Walter pauses, turns back around and shows Hank the tracking device. He says it looks just like the one they used on Gus and asks if Hank knows anything about it (""). Hank drops his pretence and stares at Walt dead seriously as he presses the controller to shut the garage door behind him. As Walt feigns ignorance he's surprised with a punch to the face that sends him sprawling to the floor. As he stands back up Hank pins him against the garage door and growls "It was you!", then expresses his disappointment with all that Walt's done to cover up his identity, mostly disgusted that he'd even killed for it. Without admitting anything Walt attempts to reason with Hank. When that fails, he reveals to Hank that his cancer has returned, and because he's dying, he wouldn't live long enough to see the inside of a jail cell even if Hank prosecuted him, so why even waste the time. Hank tells Walt to bring Skyler and the kids to his house so that he and Walt can talk after. Walter's face hardens, and he tells Hank that will never happen. Hank shakes his head and with a look of total disbelief responds that he doesn't even know who Walt is any more. Walter replies that if, indeed, Hank doesn't know who Walter is, then he should probably "tread lightly"...
- When Carol drops her groceries in the opening, oranges are seen rolling down the sidewalk. It could be yet another reference to The Godfather, where oranges are known as a sign of incoming violence.
- Oranges previously made a prominent appearance after Ted Beneke crashed into a cabinet, and a number of oranges fell on him. ("")
- In the Breaking Bad Insider Podcast for the episode, Vince Gilligan revealed that an original idea for the opening scene was to have the White residence completely gone and demolished and only the empty pool in the backyard.
- When Walter and Hank confront each other in Hank's garage, Hank is wearing a dark red shirt (a sign of aggression or death) and Walt is wearing white or light beige (symbolizing innocence or peace).
- The license plate of Walter's car reads 5BB920X, which may refer to Season 5 of Breaking Bad Episode 9, part 2.
- This episode was the series' most-watched episode at the time of its airing with 5.91 million viewers, but was later passed by "Ozymandias", which had 6.37 million.
- Walt confronting Hank with the GPS tracker mirrors him confronting Skyler with an empty cigarette packet in Season 2's "Breakage".
- Hank drinks out of a plum Fiesta mug.
- In the flash forward, Walt breaks into his former house, using a tire iron, which is what Hank used in his attempt to break into the RV in "Sunset".
- The first thing Marie audibly says to Walter when Hank walks onto the porch is "you are the devil" - referencing Hank's realization just moments ago.
- This is the last episode where Walter Jr. interacts with his uncle Hank.
- Anna Gunn's birthday is on the same date as the original broadcast, August 11. It is unknown if she watched the airing live.
- Jesse Plemons (Todd Alquist) does not appear in this episode.
- The episode is dedicated to Kevin Cordasco, a 16 year-old Breaking Bad fan who succumbed to neuroblastoma in March 2013.
Evidence observed by Hank
- The title of the episode refers to Walter White's comment that Jesse Pinkman should not take his share of the money, since it is "blood money." ("")
- The episode title may also literally reference Walt's use of barrels throughout the series. Before this episode, he would use barrels to dispose and liquefy the corpses of murdered victims into blood and other chemicals. Shortly after in the next episode, he would use barrels to hide all his drug money, which would then be buried.
- While in the bathroom, Walt folds a towel and places it under his knees shortly before vomiting. This is reminiscent of Gustavo Fring's preparation before vomiting in Don Eladio Vuente's bathroom. ("")
- Walt switching his voice tone while talking to Lydia at the A1A Car Wash is similar to Gus' handling of Walt while at Los Pollos Hermanos. ("")
- Like "", this episode features several objects and references to previous events on the show, of which they include:
- Taber Cross as Neighbor
- Jyl Murray as Car Wash Patron
- "White House Visit" by Dave Porter (as Walt walks around his former home)
- "If I Didn't Love You" by Squeeze (during the barbecue with Hank & Marie)
- "Manhattan (aka NYC Delight)" by The Longo Brothers (feat. Moe Koffman) (in the car wash while Walt talks with Lydia)
- "Wordmule" by Jim White (during Hank's montage)
- "Where Is Santa Claus" by Mr. & Mrs. Yellowman (in the background while Badger enthuses about Star Trek)
- "The Battle Hymn Of The Republic" by Chill Wills (in the background in the reception of Saul's office)
- "Patriotic" by Patricia Cory (Music is heard for a brief moment as Jesse leaves Saul’s office)
- "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...that wasn't Pinkman. You had my cell number. You killed ten witnesses to save your sorry ass. You bombed a nursing home. Heisenberg. Heisenberg! You lying, two-face sack of shit."
- ―Hank confronting Walt.
- "I'm sorry you feel this way. I want to beat this thing, I do. I'm back on chemo and I'm fighting like hell. But the truth is... in six months you won't have someone to prosecute. Even, even if somehow you were able to convince anyone that I was capable of doing these things. You and I both know I would never see the inside of a jail cell. I'm a dying man who runs a car wash. My right hand to God, that's all that I am. What's the point?"
- ―Walter White to Hank.
- Hank: "I don't even know who I'm talking to right now."
- Walter: "If that's true, if you don't know who I am, then maybe your best course... would be to tread lightly."
- ―Walter's subtle threat to Hank.