Danny gets involved when Sean becomes the latest victim in a series of robberies; Erin grows suspicious of an overworked attorney.
Frank grapples with the loss of his best friend and how best to help his daughter when she lands in jail. Danny and Erin clash.
Danny and Baez join forces with Danny's old partner when a serial killer reappears; Eddie helps a woman who accuses a sergeant of rape.
The job takes a dangerous turn for the Reagans when Eddie and Jamie deal with a domestic violence case, on the season premiere.
Danny and Jamie clash over a gang-related shooting after Jamie oversteps and Danny empathizes too closely with a victim.