主要讲述了了一对母子二十多年来的情感纠葛，儿找母、母寻子的故事，折射出当今社会一些人在金钱和利益的驱动下失去对社会的责任感、家庭的温暖以及亲人的关爱。
该剧讲述美籍华裔情报分析师亚历山大·黑尔（刘思慕 饰）发现自己的大脑遭黑客入侵，幕后黑手能看到并听到他所感知的一切。深陷情报机构与神秘黑客的夹缝中，他必须24小时保持伪装状态，既要揪出元凶又要证明自身忠诚。
性格直爽的警长米奇·福克斯是莎伦·莱昂内（《烈焰国度》角色）的继姐妹。她一边在小镇 Edgewater 的街道上巡逻，一边调查犯罪活动，同时还要应付前科累累的父亲和任性的女儿。
新興毒品「粉精靈」流竄市面，臥底潘奕風（馬貫東 飾）潛伏多年，終令真正製毒師一權世豪（杜燕歌 飾）被拘捕。但世豪金蟬脫殼獲得輕判！奕風為提防世豪出獄後會讓「粉精靈」再度肆虐，請求上司批准他組織臥底小組，調查向世豪提供原材料的上線，圖能將整條黑暗製毒鍊連根拔起。 奕風找來三名各擅勝場的臥底嬌娃一「女版福爾摩斯」沈佳琪（張曦雯 飾）、「細心敏銳武術通」江妙姿（陳瀅 飾）、「百孌行走數據庫」童小茹（羅毓儀飾），以美貌設陷阱、以感性作利刃、以智慧當盔甲，接近目標人物一表面上是慈善商家劉彪（關禮傑 飾）和卡邦妮（邵美琪 飾）夫婦，及其背後的四聯商會。四聯商會勢力龐大，滴水不漏，唯一突破點便是劉氏夫婦的女兒劉寶儀（鍾柔美 飾）。 奕風此次任務雖然獲得直屬上司禤步青（黃子雄 飾）鼎力支持，卻被鄰組警司郭宗南（黃子恆 飾）懷疑他在任臥底期間，早已變節。奕風挺著腹背受敵的壓力，卻諱莫如深的推動著三名女臥底進行各種危機重重的行動，原來奕風懷著一個自私的目的，想借這次任務，想為受涉而喪命的女友討回公道。
一辆巴士被三名劫匪劫持，但他们来不及逃走就死了。每位乘客的说法都一致，是一个兜帽男拯救了大家。随着案情展开，英雄与罪犯之间的界限开始变得模糊。
Season 5 finds Murder, She Wrote's intrepid Jessica Fletcher in fine sleuthing form, and venturing farther afield from Cabot Cove--a good thing, since at the rate the murders have been happening, that town would be nearly cleaned out. Some of the best episodes take place in more exotic locales like New York (dead man on the street, wearing just one shoe), Montana (a publishing convention gone horribly wrong) and West Virginia (two whistle-blowers at a coal company found gruesomely murdered). Angela Lansbury sparkles with determination and bonhomie, hitting her stride and then some. Jessica's own life backstory is even filled out tantalizingly, especially in the episode "The Last Flight of the Dixie Damsel," in which an investigation is launched into a mysterious cargo plane that is linked, she learns to her horror, to her late husband. The series' other delight is watching for cameos by stars of a certain age, and this season doesn't disappoint, with appearances by Roddy McDowall, Shelley Fabares, and Dinah Shore--but also some up-and-comers like Megan Mullally (proof positive that the Will & Grace whine was a put-on) and future satirist Bill Maher.
