Walter White is a high school chemistry teacher who learns that he has lung cancer. With a new lease on life, Walter becomes a drug dealer to secure his family's financial security.

Following their debacle in the desert, Walter and Jesse are left with a mess to dispose of. Later, Skyler grows suspicious of Walt's recent activity.

Walter is left to deal with Krazy-8 alone following an argument with Jesse. After Marie raises concerns that Walt Jr. is smoking cannabis, Hank shows him the dangers of drug use.

The DEA becomes suspicious of a new drug kingpin. Walt reveals that he has cancer to Marie and Hank. Elsewhere, Jesse visits his estranged family.

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

The side effects of chemo begin to plague Walt, who is also cooking meth again. Jesse's friend, Skinny Pete, introduces him to a distributor named Tuco, but things go awry and Jesse ends up hospitalised.

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.