After Gustavo Fring turns from his car and leaves the parking garage, Walter White rushes to disarm the bomb and remove it from the vehicle. He then enters the hospital and talks with Jesse Pinkman, asking if he can think of any other place to catch Gus off guard. As they talk, two detectives approach Jesse and take him to interrogate him about the ricin hint.
Detectives Kalanchoe and Munn interrogate Jesse and he asks to call his lawyer, Saul Goodman. At the same time, Walt breaks into Saul's office to try and find a way to contact him since he fled. Saul's secretary extorts him for $20,000, and when he balks at the amount, $25,000 for the information. He returns to his house to get the money but, realizing that Gus may have staked the place out, parks down the street and sends his unwitting neighbor, Rebecca Simmons, to check the house for him (he tells her that the family is on vacation and Walter White Jr. thinks he left the stove on). His suspicions are right; shortly after she enters the house, a pair of gunmen, Harris Boivin and Raymond Martinez, quietly sneak out through the back gate. After a few brief minutes, the neighbour leaves, and Walt sneaks in the backdoor into the crawl space to get the $25,000 and narrowly avoids the hitman pair who enter shortly after him.
Back at the police station, Saul enters the interrogation room, sending the detectives out the room, and confers with Jesse - does he have any info that might help Walt reach Gus. Jesse tells him to pass on the only info he can think of —that Gus visits Hector "Tio" Salamanca at the Casa Tranquila nursing home. Walt ponders this information and decides to use Hector's hatred of Gus to his advantage. He meets with Hector. After Walt has left, Hector calls a nurse and spells out a message: "Need DEA". Later, Steven Gomez visits Hank Schrader, who is still under heavy DEA protection, and informs him that Hector has important cartel information and will only speak with Hank. At the DEA office, Hector spells out "S-U-C-K-M-Y" and "F-U-C-" before Hank calls it off and sends Hector back to the nursing home, with Hank quipping "Well, at least he didn't shit himself this time." Tyrus Kitt, who is keeping an eye on Hank, sees Hector being loaded into the van at the police headquarters. Tyrus then informs Gus that Hector was acting as an informant to the DEA, playing into his and Walt's trap. After Hector is returned to the nursing home, Tyrus enters and sweeps the place for bugs and cameras. The police inform Jesse that ricin was not found in Brock Cantillo's blood, so luckily for him he's free to go.
On the sidewalk, Jesse is tazed and abducted by two of Gus's men. Tyrus calls Gus to report both Jesse's kidnapping and Hector's betrayal to the DEA. He willingly offers to take care of the situation with Hector himself, but Gus vetoes his suggestion, saying "I do this". Fring leaves for the nursing home.
He arrives shortly thereafter and waits in the parking lot while Tyrus checks the room for unexpected surprises. Upon getting the "all clear" signal, Gus walks into the nurse home and enters Hector's room. Gus berates Hector for his supposed "cowardice", calling him "a crippled little rata (rat)". Tyrus prepares a syringe and hands it to Gus. "Last chance to look at me," Fring pridefully says, before letting out a sarcastic sigh. As he brings the needle closer to Hector's arm, Hector actually, for the first time in many years, looks dead into Gus's eyes with a gaze of remorse. Gus is shocked, though Hector's expression soon changes to a face of wrath and starts sounding his bell repeatedly.Gus, at first, is bewildered but soon, alerted by the blinking of a tiny light, realizes that Hector has a bomb fitted to the wheelchair, rigged to blow up by ringing the bell. He shoots up out of his seat and yells, but the bomb explodes, blowing down the door to Hector's room and sending debris into the hallway of the nursing home. Miraculously, Gus has survived and he calmly walks out of the destroyed room then adjusts his tie, seemingly unharmed. But then nurses run up, shocked with horror: the camera swings to Gus' right side, and we see that the right half of Gus's face has been blown off by the bomb, leaving skull, jaw, and brain exposed. He falls to the floor, dead.
In a long-term parking lot outside the Albuquerque airport, Walt is listening to the radio news report which is breaking the story about the explosion. The only salient detail at the time is that "as many as three people may have been killed." Smiling, Walt pulls out of the lot.
Down in the superlab, Jesse prepares for another batch while one of the thugs who kidnapped him sits around monitoring him with a gun. The lab's elevator sounds and the thug forces Jesse to handcuff himself to one of the chemical tanks while he goes to check it out. Upon unlocking the elevator door, the thug's partner appears with Walt popping up from behind him and shooting both men. Jesse hears three gun shots and sees Walt walk around the corner; the blood of the two thugs spattered on his face. "Gus is dead," he says to Jesse. "We've got work to do."
The two then open every chemical container in the lab, flooding the floor with a dangerous mix, then rig a Christmas light timer to a frayed wire and exit the lab. They wipe down the machinery for prints and pull the fire alarm as the chemicals ignite downstairs. Walt yells "Vamonos" to the laundry workers and as they flee, the superlab lab below explodes.
Walt and Jesse meet on the roof of the hospital's parking garage. Jesse tells Walt that Brock is going to recover, and that it was not ricin, but Lily of the Valley that poisoned Brock - a flower with poisonous berries that children sometimes think to be edible. Walt reassures him that Gus needed to die nonetheless. Walt calls Skyler, who has learned about the nursing home explosion on TV and, weary of the reply, asks if he had anything to do with it. He replies simply: "I won". Eyes widening, Skyler wordlessly reacts with fear and horror, realizing what her husband is capable of. Walt hangs up the phone and drives away. As he passes Gus' Volvo, still parked in the hospital parking lot, he smiles as the camera focuses on the 'Los Pollos Hermanos' air-freshner hanging from its rear-view mirror. In Walt's backyard, the camera slowly pans towards a large flower pot where a plant with delicate hanging bell-shaped white flowers is growing. The label pegged between its leaves reads : "Lily of the Valley."
- Lily of the Valley (Convallaria majalis) is indeed a poisonous plant, where all parts of the plant - from its red berries / rhizomes / leaves / stems / to its intoxicatingly scented little white flowers - are toxic with over 40 cardiac glycosides. ... The reveal of the plant is silent proof that Walt was in fact lying to Jesse in the previous episode, and did indeed betray Jesse in order to manipulate him.
- Another LOTV legend claims the plant sprang from the blood of St. Leonard of Noblac as he battled a dragon. Even this "battling of a dragon" theme is nicely analogous to Walt's battling of his dragon - Gus.
- In his final moments, Gus Fring bears a striking resemblance to the Batman villain Two-Face. This is likely a tongue-in-cheek reference to Fring's double life and treacherous nature.
- The episode's title refers to the final showdown between Walt and Gus, but can also be seen as a play on words regarding Gus' demise - where half of his face is burnt off.
- Gustavo Fring is the first main character to die.
- Jesse mentions the medical show House, M.D. while he is being questioned by the police. House often featured patients whose symptoms were the result of poison derived from an unusual source - ergot, organophosphates, toad eggs and methyl bromide were all featured, but neither ricin nor Lily of the Valley ever were.
- The woman who plays the Whites' neighbor, Rebecca Simmons, is Vince Gilligan's mother, Gail Gilligan.
- Extended on home video. The episode was a few minutes too long, and the clip of Gilligan's mother was cut to shorten the time. It was only seen on the original premiere of the episode. The scene was restored on the home video release.
- The scene where Walter drops his gun after killing the men in the lab mirrors the scene where Gus drops the boxcutter in Box Cutter.
- Walt employs the old proverbial tactic of "The enemy of my enemy is my friend," when he decides to use Hector Salamanca to help him kill Gus. Hank later uses the same tactic when he teams up with Jesse in an attempt to arrest Walt.
- The music in the scene where Gus walks towards the Casa Traquila nursing home is "Goodbye" by Apparat. Appropriately, the Apparat album on which this track can be found is called "The Devil's Walk".
- A photograph can be seen of Hector with twin infants and a psychotic-looking child, these being Marco, Leonel and Tuco when they were young.
- Erika Viking was a real DJ on Coyote 102.5 at the time of filming.
- This is the third episode to be written and directed by Vince Gilligan, after "Pilot" and "Full Measure".
- Casa Tranquila - Where Walt goes to meet Tio Salamanca & offer revenge on Fring is located at 8820 Horizon Blvd.
- The abandoned white building where Walt meets Saul.
- After the Casa Tranquila explosion Walt is listening to the radio in a parking lot. You can see 2 yellow airport parking shuttles and a large building in the distance. This is the same view from the Airport Parking lot right off the expressway.
- "Crawl Space" by Dave Porter (as Walt retrieves some money from his home)
- "Here is Fritz's Polka Band/The Party's Just Begun [From "The Big Joe Polka Show"]" by Fritz's Polka Band (when Walt visits Hector at Casa Tranquila)
- "Monaco" by Bill McGuffie (while Hector tells the nurse that he wants the DEA)
- "I Wonder" by Erik Janson & Bevan Manson (when Hector returns to Casa Tranquila)
- "Dreams of You" by Alan Moorhouse (while Tyrus inspects Hector's room)
- "Goodbye (Instrumental)" by Apparat (as Gus enters Casa Tranquila)
- "Fourth Floor, Ladies Shoes" by Daniel May (as Gus leaves Hector's room)
- "Freestyle" by Taalbi Brothers (while Walt and Jesse prepare to torch the lab)
- "Black" by Danger Mouse and Daniele Luppi (feat. Norah Jones) (after Walt has spoken on the phone with Skyler)
- Many months of preparation took place for the the visual effect of Gustavo Fring's facial wounds, with assistance from the special effects team from the AMC drama The Walking Dead. In order to produce the effect, elaborate makeup was used on Giancarlo Esposito's face, and combined with computer-generated imagery that took two separate shots and combined them in post production.
- Skyler: "Jesus, Walt, the news here. Gus Fring is dead. He was blown up along with some person from some Mexican cartel, and the DEA has no idea what to make of it. Do you know about this? Walt? I need you to–"
- Walter: "It’s over. We’re safe."
- Skyler: "Was this you? What happened?"
- Walter: "I won."
- — Walt and Skyler talking on the telephone.