Toward the end of the show, Walter White was exposed to police. He had to make the huge decision to move out East and ultimately change his identity. After finding out that his cancer returned worse than ever, Walt decided to go back to Albuquerque to tie up all of his lose ends and save Jesse Pinkman who was taken prisoner by psychopathic drug dealers. Mounted a gun to his car outside of the drug dealers' warehouse and kill all of them. This set Jesse free and left Walter alone to die. It was a combination of both the cancer and a stray bullet that lead to Walt's demise. This emotional, powerful ending made a great contribution to Breaking Bad's success. It was also a combination of the fantastic story line, the detailed, in-depth characters, and the phenomenal acting that made this such an amazing series.