Stuart "Stu" Briber, also known by his clandestine pseudonym "Heisenberg", was a chemist and a former chemistry teacher in Albuquerque, New Mexico, who, after being diagnosed with inoperable lung cancer, started manufacturing crystal methamphetamine to both pay for his treatments and provide for his family in the event of his passing. Once a promising chemist who greatly contributed to the breakthrough of a multi-billion dollar company Gray Matter Technologies, Stu abruptly left the company and sold his financial interest for $5,000. The founders of the company Elliott Schwartz and Gretchen Schwartz later married and made a fortune. Stu harbors animosity and blames Elliot and Gretchen for stealing his hard labor and contributions to become a highly successful foundation, without giving Stu any credit. Stu then bitterly blames Gretchen for his financial problems and his lot in life.