Season three of CITY ON A HILL brings us to Boston's high society Beacon Hill. Having left the FBI and thrown his badge into Boston Harbor, Jackie Rohr (Bacon) lands a lavish new gig running security for a wealthy family. Life is good until secrets begin to unravel. When an investigation opens, ADA Decourcy Ward (Hodge) sees an opportunity to finally rip out the machinery perpetuating a broken criminal justice system. Siobhan Quays (Banks), representing a construction worker who was severely injured on the Big Dig, encounters the city's corruption firsthand, all while coping with the traumatic events of her past year. As Jenny Rohr (Hennessy) can attest, given her history with her father, some experiences will haunt you beyond your breaking point.

　　本剧改编自原著“科莫兰·斯特莱克”系列的第五本《混沌之血》。
　　私家侦探Cormoran Strike正在康沃尔探亲，一位女士找到他，希望他帮忙寻找自己在1974年神秘失踪的母亲Margot Bamborough。
　　Strike以前从未处理过悬案，更不用说40年前的案件了，但尽管成功的机会渺茫，他还是很感兴趣，于是接手了这起案件，这成了他和搭档Robin Ellacott正在处理的一长串案件中的又一起。而Robin本人也正忙于应付一团糟的离婚和多余的男性关注，同时还要与自己对Strike的感觉作斗争。
　　在Strike和Robin调查Margot失踪案的过程中，他们遇到了一个极其复杂的案件，其中有一个变态连环杀手和一些不可信的证人。他们了解到，即使是几十年前的案件也可能被证明是致命的。

　　Follows two friends who love having fun and booze, until everything unravels.