After being diagnosed with terminal lung cancer, high-school chemistry teacher Walter White wants to ensure financial stability for his pregnant wife Skyler and his disabled son, Walter Jr. He teams up with a former student, Jesse, and starts cooking Albuquerque’s finest meth. They encounter a few troubles with local drug dealers, but they continue their endeavors despite all the setbacks.
At first, Jesse tries to sell the high-quality product to drug-distributor Krazy-8. However, the distributor proves he truly is worthy of his nickname and attempts to snatch them both with the help of his cousin Emilio. Believing that they’re planning to kill him, Walt poisons his attackers. He kills Emilio and captures Krazy-8, whom he also ends up murdering later on.
Walt is disappointed with Jesse’s unprofessional attitude, so he decides to end their collaboration. Jesse tries to replicate Walt’s meth formula, failing miserably. Meanwhile, Walt’s family persuades him to undergo treatment for his cancer. He refuses at first, but eventually accepts. However, Walter turns down financial assistance from both his brother-in-law, Hank, and his former work partners, Gretchen and Elliot Schwartz. Instead, he decides to work with Jesse again. He tells his family that the money he’s making actually come from the Schwartzes.
Walt and Jesse agree to divide the work. Walt sticks with manufacturing meth, while Jesse distributes it. Jesse gets in touch with a new drug dealer, Tuco, who only agrees to work with Walt (who now goes by the alias Heisenberg) after the latter threatens him and causes an explosion in Tuco’s hideout. Later on, Jesse and Walt face difficulties with finishing the amount of meth promised to Tuco. They break into a warehouse to steal a large barrel of methylamine, necessary to produce more meth in a shorter period of time. When they deliver this new product though, Tuco brutally beats up one of his associates for speaking out of line. This leaves our protagonists shocked and frightened for their lives.
Walter and Jesse are kidnapped by Tuco and his uncle Hector, but they’re able to escape before Hank and other DEA agents arrive to kill Tuco and arrest Hector. Later, they decide to expand their business and hire the corrupt lawyer Saul Goodman to handle their legal issues. Meanwhile, Walt finds out he’s getting better, but he’s still facing insurmountable medical bills from his cancer treatment. Walter and Jesse drive a recreational vehicle into the desert and produce meth for four days straight.
Saul arranges a meeting between Walt and the head of a large-scale drug-dealing business, Gus Fring. Gus offers to buy the meth batch for 1.2 million dollars if Walt is able to deliver the product in the next hour. Walt hurries to Jesse’s apartment and finds him passed out with his girlfriend and neighbor Jane, due to heroin abuse.
Walt is able to deliver the meth on time, but is unwilling to pay Jesse his share because of his current lifestyle. Jane threatens to expose Walt if he doesn’t bring them the money. He finally agrees, but he returns that same night only to find them passed out again. When he tries to wake up Jesse, he accidentally causes Jane to suffocate. Because he thinks she’s a bad influence on his partner, Walt sits idly beside her and lets her die. Jesse eventually goes to rehab.
Meanwhile, Skyler becomes suspicious over her husband’s lies. She confronts Walter about his frequent absences and excuses, demanding that they separate.
Walter tells Skyler about his secret career as a drug dealer and offers to divorce her to avoid causing her any trouble. However, Skyler recognizes she is in too deep and tries to find a way to launder their money with the help of Saul. Gus offers Walt a big chunk of money to work with him again in an underground lab. They would be joined by new partner, Gale. Walt agrees after he learns that Jesse got out of rehab and is cooking meth on his own in their RV.
Hank is still on the “Heisenberg” case, slowly gathering evidence to arrest Jesse. He discovers proof that links the RV to the meth production. While he’s working on getting a warrant, Walt warns Jesse and they destroy the RV together. In the meantime, Tuco’s cousins come to take revenge for his death, but Gus leads them to Hank instead of Walt. They shoot Hank and leave him paralyzed from the waist down.
Walt is able to convince Gus to bring Jesse back to work as his partner, claiming that he’s more effective than Gale. However, Jesse begins to steal meth from the lab and sell it in secret on the side. He also starts dating Andrea, whose younger brother Tomas is involved in Gus’ street dealing. Jesse confronts Gus and urges him to stop using children in his business. However, he later finds Tomas dead and assumes Gus’ dealers are at fault. Nonetheless, Walter runs them over before Jesse gets the chance to kill them himself.
Jesse goes into hiding and Gus loses his trust in Walt. He brings back Gale to work as Walt’s partner. Later on, Walt discovers that Gale is trying to learn the meth recipe, which would make Walter expendable to Gus. Walt and Jesse secretly meet up and decide to find Gale’s apartment and murder him. However, Walt is kidnapped by Gus’ associate Victor and his private investigator Mike and brought back to the lab. Realizing he’s about to be murdered, Walt convinces his attackers to let him call Jesse. He asks him to murder Gale himself. Jesse hurries to Gale’s apartment and shoots him.
Following Gale’s death, Gus increases security at his underground lab by installing cameras to monitor Jesse and Walt. Meanwhile, the DEA finds evidence that links Gale to Gus, which leads Hank to start suspecting that Gus is involved in a meth-dealing operation. He also finds a notebook containing information on how to cook meth with the inscription “W.W.”
Later on, Mike, one of Gus’s enforcers, starts using Jesse for protection during his dead-drops. Gus also orders him to go teach the cartel scientists how to produce the blue meth, rendering Walt useless. Gus fires Walt and tells him to take care of Hank, threatening to kill his family.
Walt prompts Jesse to poison Gus with ricin, but Jesse fails to deliver. Then, Jesse finds out that Andrea’s son has been poisoned and blames Walt for it. However, Walt convinces him that it was probably Gus. Then, Walt rushes home to tell his wife they need to escape and warns Hank anonymously. However, he finds out that Skyler spent his savings trying to keep the IRS away from her money-laundering business.
The whole family, including Hank, are put under protective custody. Walt refuses the protection and plans to find a way to get rid of Gus once and for all. He tries to bomb his car, but fails. He then puts a bomb on former cartel enforcer Hector Salamanco – when Gus goes to meet Hector, the bomb goes off and they both die. Later, we discover that Walt is actually the one who poisoned Andrea’s son, to turn Jesse against Gus.
After Gus’ death Walter, Jesse, and Mike start working together. Walt and Jesse produce meth in tented houses, while Mike manages the business aspect of the operation. The DEA starts tailing Mike. Eventually, Walt murders him and hires the leader of a neo-Nazi gang called Jack Welker to take care of business. Skyler takes Walt’s children out of the house when she discovers he’s back to dealing meth.
Later, during a family dinner, Hank discovers a book in Walt’s bedroom dedicated to “W.W.” and realizes he is Heisenberg. Hank tries to make Skyler confess, but isn’t successful. After getting sick of Walt’s corruption, Jesse decides to help Hank and the DEA capture him. The DEA ambushes Walt during a meeting with Jesse in the desert, but Walt manages to call Jack’s crew. However, Jack kills Hank, captures Jesse, and steals most of their money.
Everyone learns about Hank’s death and holds Walt accountable, including Walt Jr., who at this point wants nothing more to do with his father. Walter flees and spends the next few months in a cabin, where his health deteriorates because of his cancer. He eventually returns to town to visit his family and goes to the compound where Jesse has been enslaved by Jack and his crew. He kills everyone and is able to free Jesse, who then manages to escape before the police arrive at the scene. Walt gets shot and surrenders to his injury.