S1E6 · Crazy Handful of Nothin'

Complete story — includes the ending

Walt undergoes his first chemotherapy session. Walt and Jesse continue their agreement in which Walt will cook the meth while Jesse handles sales. When Walt removes his shirt during a cooking session, Jesse recognizes the radiation therapy marks on Walt's chest and deduces that he has lung cancer. Meanwhile, Hank ties the recovered respirator to Walt's high school's chemistry lab. Hank falsely arrests the kindly school janitor on charges of stealing equipment, who has a criminal record for drug possession and had a small amount of marijuana in his car. Walt shaves his head when he discovers that his hair is falling out. When their initial batch of meth only yields $2,600, Walt insists they need to ramp up production. Jesse's friend Skinny Pete introduces him to the distributor who replaced Krazy-8: psychopathic drug lord Tuco Salamanca. When Jesse demands up-front payment for the meth, Tuco severely beats him and steals the meth. Walt later confronts Tuco on his own, causing an explosion in his hideout, and forces him to pay for the stolen meth. Impressed, Tuco agrees to work with Walt.