SeasonthreeofCITYONAHILLbringsustoBoston'shighsocietyBeaconHill.HavinglefttheFBIandthrownhisbadgeintoBostonHarbor,JackieRohr(Bacon)landsalavishnewgigrunningsecurityforawealthyfamily.Lifeisgooduntilsecretsbegintounravel.Whenaninvestigationopens,ADADecourcyWard(Hodge)seesanopportunitytofinallyripoutthemachineryperpetuatingabrokencriminaljusticesystem.SiobhanQuays(Banks),representingaconstructionworkerwhowasseverelyinjuredontheBigDig,encountersthecity'scorruptionfirsthand,allwhilecopingwiththetraumaticeventsofherpastyear.AsJennyRohr(Hennessy)canattest,givenherhistorywithherfather,someexperienceswillhauntyoubeyondyourbreakingpoint.