How exactly did Walter White poison young Brock in Breaking Bad? The incident took place in season 4 of the AMC hit-series but the truth didn't come out until the following year. Since then, the show's creator Vince Gilligan has provided insight into what viewers didn't see with the poisoning.
The character of Brock Cantillo (Ian Posada) was the six-year-old son of Jesse Pinkman's girlfriend, Andrea. Jesse met Andrea at a Narcotics Anonymous meeting in Breaking Bad season 3 and the pair eventually struck up a relationship. He greatly admired Brock and the two would often hang out and bond over video games. After Jesse and Andrea broke up, he continued to send them money through Saul Goodman so they could afford a better living situation. The pair reunited in season 4 but shortly after, Brock was rushed to the hospital with a serious illness.
At first, Jesse believed that Brock was given the ricin that was intended for Gus Fring; he thought that Walt stole the ricin and gave it to Brock as a way to punish Jesse for getting too close with Gus. When confronted, however, Walt gave Jesse the idea that it must have been Gus who used the ricin to harm Brock. In the sad reality, Jesse was right; Walt did cause Brock's illness as a way to turn Jesse against Gus. But the poison wasn't caused by ricin as later confirmed, it was from a Lily of the Valley plant, revealed to be in Walt's backyard in the final shot of Breaking Bad's season 4 finale. But how exactly did he poison Brock with berries from the plant?
Gilligan provided more details regarding the poisonous ploy at San Diego Comic-Con in 2013. The writers of Breaking Bad referred to the incident as Walt becoming the "Evil Juice Box Man," imagining him injecting the poison into Brock's juice box. Off camera, Walt had somehow planted the juice box in Brock's lunch at school, making sure only he came in contact with the drink. The rest of the plan involving the ricin stolen by Huell then played out on-screen.
Brock ultimately survived the illness and made a full recovery. Walt later encountered Brock at a dinner gathering where he seemed very uneasy around the young boy. His actions have obviously caused a lot of guilt for how he used a child's health to mess with Jesse. Many fans even consider Brock's poisoning the moment when Walter White turned into a full-fledged villain in the series. Jesse eventually put the puzzle pieces together and figured out that Walt was responsible, causing an enormous amount of turmoil between the two men.
After Andrea was killed by Todd as a form of punishment from Jesse's escape, it's not known what happened to Brock. It's presumed that he was taken in by his grandmother. After Jesse got a taste of freedom in the Breaking Bad series finale, many thought he would find Brock and take care of him as a way to honor Andrea. Since Jesse Pinkman is rumored to be at the center of the upcoming Breaking Bad sequel movie, maybe fans will also see the return of Brock Cantillo.