[1] In the episode, Maggie (Lauren Cohan) and Lydia (Cassady McClincy) help Aaron (Ross Marquand) and Gabriel (Seth Gilliam) on a rescue mission.
With his mother, Pamela cutting off his line of credit, Sebastian (Teo Rapp-Olsson) forces Daryl (Norman Reedus) and Rosita (Christian Serratos) to get a sum of money from a walker-infested house after threatening Judith, R.J.,& Socorro.
Hiding in Maggie's van, Hershel (Kien Michael Spiller) is rescued by Negan and forces him to confess to Glenn's murder, and almost kills him before being convinced.
The group corners and Aaron kills Carlson (Jason Butler Harner), and it is revealed that Leah (Lynn Collins) was the one who broke into the caravan and stole the Commonwealth's weapons.
[2] Paul Dailly of TV Fanatic gave a score of 4 to 5 points praising the episode, writing: "["The Rotten Core"] featured a nice blend of action, high-stakes, and revelations about the Commonwealth and Negan.