The Walking Dead has been following the comic book source material written by Robert Kirkman to the best of its ability since the times where Rick Grimes left and Carl Grimes died. Showrunner Angela Kang inherited an AMC series with little room to follow those comics with so many major actors leaving the series and changes having been forced upon her. Still, the series has maintained the essence of the comics in the overarching story while also packing in a few surprises which organically fit into the story being told on television. One of those source material threads was an encounter between Negan and Brandon folllowing the former villains escape from prison but it went down quite differently on the show.
Spoilers for The Walking Dead Episode 10x05 follow. Major spoilers!
In Sunday night's What It Always Is episode of The Walking Dead, Negan's jailbreak was carried out with Brandon. Brandon on the TV series is not the son of Tammy and Earl as he was in the books. Instead, Brandon is the son of a Savior who was killed during the All Out War story which pitted Rick Grimes against Negan. This character's goals are to bring the Saviors back to their glory days, not seek revenge against the Whisperers as he wanted in the books.
Still, the outcome of the story remains the same. Negan is out of jaill and Brandon is dead. Brandon's death, however, is also a major change from the books and it seems to be in service to Negan's redemption arc on the TV series. Early on, many fans fuly rejected the notion of such an arc for the villain not only because of the murders of Glenn and Abraham but also because of how he was portrayed in the episodes which followed.
In the comics, Negan manipulated Brandon as a means to get him out of jail. When he was done with the kid, he stabbed him with a knife and went on to meet the Whisperers.
On the TV series, Negan tried to calm Brandon's excitement over bringing the Saviors back and sent him back to Alexandria. When Brandon saw this as a test to prove his willingness to become a Savior and killed a woman and her young son, Negan took it upon himself to kill the annoying character who wouldn't leave him alone. Negan made it clear, he would "never kill a kid" when he spoke of Carl Grimes and the story which accused him of causing his death directly. When the young boy Milo was killed in Episode 10x05, Negan's trigger was pulled and he killed Brandon with a rock.
The Walking Dead airs Sundays at 9pm ET on AMC.