When an unassuming high school chemistry teacher discovers he has a rare form of lung cancer, he decides to team up with a former student and create a top of the line crystal meth in a used RV, to provide for his family once he is gone.

Walt and Jesse attempt to tie up loose ends. The desperate situation gets more complicated with the flip of a coin. Walt's wife, Skyler, becomes suspicious of Walt's strange behavior.

Walter fights with Jesse over his drug use, causing him to leave Walter alone with their captive, Krazy-8. Meanwhile, Hank has a scared straight moment with Walter Jr. after his aunt discovers he has been smoking pot. Also, Skylar is upset when Walter stays away from home.

Walter finally tells his family that he has been stricken with cancer. Meanwhile, the DEA believes Albuquerque has a new, big time player to worry about. Meanwhile, a worthy recipient is the target of a depressed Walter's anger, and Jesse makes a surprise visit to his parents home.

Walter and Skyler attend a former colleague's party. Jesse tries to free himself from the drugs, while Skyler organizes an intervention.

The side effects of chemo begin to plague Walt. Meanwhile, the DEA rounds up suspected dealers.

Walter accepts his new identity as a drug dealer after a PTA meeting. Elsewhere, Jesse decides to put his aunt's house on the market and Skyler is the recipient of a baby shower.

Walt and Jesse are vividly reminded of Tuco’s volatile nature, and try to figure a way out of their business partnership. Hank attempts to mend fences between the estranged Marie and Skyler.

Walt and Jesse find themselves in close quarters with an unhinged Tuco. Marie and Hank comfort Skyler, who is distraught over Walt’s disappearance. Hank pays a visit to Mrs. Pinkman on some not-so-official business.

Walt and Jesse become short on cash when they try to cover their tracks. Meanwhile, the DEA has a lead that could them straight to Walt and Jesse.

Walt attempts to reconnect with his family, while Jesse struggles to rebuild his life.

Hank suffers from the aftermath of his encounter with Tuco. Meanwhile, Jesse hires a crew to get their product out on the streets.

Walt's secret is in jeopardy when Skyler thanks Gretchen for paying for his treatment.

Jesse and Walt discuss expanding into new territories; Hank struggles to fit in; Skyler pursues a new job opportunity; Jesse gets to know his landlord.

Walt and Jesse seek advice from a shady attorney when Badger gets in trouble with the law; the DEA believes they have caught up with "Heisenberg" ; Hank returns.

Walt and his family wait for news after he undergoes a PET-CT scan. Walt follows Saul's advice; Jesse's relationship with Jane is put on hold when he and Walt head to the desert for a marathon of cooking.

Walt and Hank get into a heated argument at a party. Skyler opens up to her boss. Jane hides her relationship with Jesse from her father.

As the end of her pregnancy finds Skyler conflicted about her feelings, a dealer's death forces Walt to look for somewhere to unload a load of meth.

As Walt explores money laundering options, he and Jesse spar over the profits from their latest deal. Jesse and Jane clash with her father. Walt makes a fatal decision.

Skyler confronts Walt about his secrecy; Jesse falls apart; and Jane's grief-stricken father takes action that results in further tragedy.