Wikipedia Website in Breaking Bad Season 3 Episode 12: Half Measures (2010)

Walter White, a high school chemistry teacher, is diagnosed with Stage III terminal lung cancer. Paunchy and balding and barely 40, he’s a far cry from the man he used to be. He deals with his transformation by deciding to cook crystal meth – and in so doing taps into his true energy and genius. He teams up with Jesse Pinkman, a former student that he once got in trouble for turning on another teacher. The two face several hurdles in their new business – difficulties getting financing, hiding from the police, and eliminating anyone who threatens them or gets in their way.