Walter Hartwell "Walt" White Sr. (also known by his alias Heisenberg) is the main character of the TV series Breaking Bad. Walter also has a small appearance in its spin-off series Better Call Saul's sixth and final season.
Walt was a chemistry genius who helped start up a big science company, Gray Matter Technologies, before he left the company. He later becomes a chemistry teacher who doesn't make enough money and has to work at a car wash, which he hates. Walt learns he has lung cancer and is about to die soon. For Walt's 50th birthday, his brother-in-law Hank Schrader, who works for the Drug Enforcement Administration (DEA), takes Walt to see his job of busting drug dealers. Walt is interested and wants to start cooking meth to make enough money for his family before he dies of cancer. He meets Jesse Pinkman, a drug dealer who used to be his student, and asks to be partners.
Walt kills two drug dealers, Emilio Koyama and Krazy-8, after they try to kill him. Walt and Jesse get an RV and start cooking meth, which is excellent because of Walt's chemistry skills, and Walt keeps lying to his wife, Skyler White, and the rest of his family including Hank. Walt and Jesse meet Tuco Salamanca, a wild and violent drug dealer. They try to get their meth to Tuco so he can sell it, but Tuco's too crazy. Tuco kidnaps Walt and Jesse and wants to bring them to Mexico to keep cooking meth. Hank shows up and kills Tuco, and Walt and Jesse escape.
One of Jesse's friends, Badger, gets arrested by the DEA for selling Walt and Jesse's meth. Walt hires Saul Goodman, a lawyer who is also a criminal, to get Badger out of jail. Saul sets Walt and Jesse up with a drug lord named Gustavo "Gus" Fring. Gus asks Walt to cook meth for him, and he'll give him $3 million if Walt does it for 3 months. Walt takes the deal and stops being partners with Jesse for a little while.
Walt works with a smart chemist named Gale Boetticher to cook good meth for Gus. Walt finds out that Hank knows about the RV and tries to destroy it, but Jesse gets angry because he wanted to use the RV to start his own business.
Walt has Jesse kill Gale after Gus plans to kill Walt because it would be bad for the business. After Walt is fed up with Gus, he has Hector Salamanca as a human bomb and explodes Gus, killing him. He soon meets Jack Welker and his gang, which includes Todd Alquist. After Todd kills a kid in the desert and Jesse's friend Andrea at her home, Jesse strangles Todd to death with his handcuff chain. In the desert, Jack shoots Hank dead after Walt tries to save him, but by then Hank had already accepted his fate, so it was too late.
In the finale, "Felina," Walt makes Jack bring Jesse out so he can kill him, but he saw the condition he was in and decided to save him by tackling him to the floor and shielding him from the bullets his M60 was about to start shooting out after he opened his car trunk. The M60 obliterates the gang before Jesse strangles Todd to death. Walt took his final, most personal shot to Jack's head while he begged on the floor like a dog.
Walt was struck by one of the bullets from the M60 and later died, ending Breaking Bad.