Walt begins his chemotherapy and returns to cooking crystal meth with Jesse. Soon Jesse is selling their superior product on the street but he only manages to sell an ounce making each of them only $1300. Walt pushes him to be more imaginative and find a distributor to whom they can sell in bulk. Against his better judgment, Jesse approaches Krazy 8's replacement as a drug wholesaler, a big time operator named Tuco who doesn't quite do business the way he had expected. It's left to Walt to sort it all out, telling Tuco his name is Heisenberg. Walt's having a hard time dealing with his chemo and is frequently ill. DEA agent Hank traces the gas mask they found in the desert to Walt's high school and makes an arrest.