It's Hood Day on the streets of Los Angeles, and Captain Rucker has the department playing hall monitors. Sammy lets old grudges die hard when he leaves a gang territory unattended, only to have a violent gang war erupt throughout the city. Ben's recent mistake continues to haunt him everywhere he goes. Ruben practices his speech for his daughter's Quinceañera in the midst of a murder investigation. Cooper and Tang investigate a robbery in a strict Orthodox Jewish home, leading Tang to reveal parts of her past.

John tries to save a suicidal teen in a situation that hits extremely close to home. Sammy convinces a former addict to be an informant, with devastating consequences. Tang gets a visit from someone in her past. Lydia and Ruben investigate a supposed home invasion that appears to have been staged to cover up murder.