Things are gonna change with Joel Rucker as the new captain. Lydia and Ruben investigate a convenience store murder, and Lydia uses her typical compassionate charm to collect facts on her suspect from an unassuming grandmother. Meanwhile, John and Jessica get to test their physical abilities when they're attacked on the street. Elsewhere, Sammy and Ben ride with a mistake-prone officer, but Ben is the one making mistakes... mistakes that earn him some notoriety.