Walter White celebrates his 50th birthday with his pregnant wife Skyler and teenage son Walter Jr. before teaching high school chemistry. During his second job at a car wash, Walt suffers a coughing fit and collapses. Doctors diagnose him with Stage 3 terminal lung cancer. Walt joins his DEA brother-in-law Hank Schrader on a methamphetamine lab raid, where agents arrest cook Emilio while Walt spots his former student Jesse Pinkman escaping through a window. Walt tracks down Jesse and proposes a partnership: Walt will cook crystal meth using his chemistry expertise while Jesse handles sales and distribution. They set up a mobile lab in an RV in the desert, where Walt's superior chemistry skills produce exceptionally pure product. Jesse arranges a meeting with Krazy-8, Emilio's cousin and local distributor, to establish distribution. When Emilio recognizes Walt from the DEA raid, he and Krazy-8 plan to kill both partners. Jesse panics and tells Walt to run but knocks himself unconscious. Walt pretends to teach the dealers his recipe, then kills both men by releasing phosphine gas in the RV and drives away, leaving Jesse behind.