Janet is promoted to sergeant but steps down to give it to Rachel as she feels she is needed more at home. The pair join the search for eighteen year old Robin McKendrick, a simple lad reported missing by his boss, landlord John Rivington. Pub regulars are unforthcoming until a boy called John tells Janet that an ex-soldier known as Jackie-Boy locked Robin in his car boot as a cruel prank. He later reported the car as stolen. Another witness claims that Jackie- Boy dumped his car in a quarry with Robin still in the boot. In the process of the investigation Gill identifies another body found in the river, that of Mandy Sweeting, who disappeared two decades ago.

LAPD重案组继续工作，之前谋杀Rusty的杀人狂逃离美国，不知第四季长线要如何安排。组员们在此季中归来，实在让喜欢它的观众倍感兴奋。 从Closer发展出的衍生剧，没想到该走脉脉温情路线后仍然凭一票老戏骨演员撑起了此剧，不是大红大紫，但让人看了温暖。

狄仁杰、李元芳、杨戬、扁鹊四人受女帝所托，成立峡谷重案组维护王者峡谷的秩序，但是诡谲的案件接连不断，李元芳和杨戬甚至无辜受到暴君的攻击直至昏迷。真相看似毫无遮掩实则扑朔迷离。李元芳与杨戬平安醒来，重案组似乎回到了平稳的日常。但峡谷里暗流汹涌未曾停歇，黑幕仍未分明。敌暗我明，狄仁杰要如何带领众人破局？

In the fourth season of this award-winning show, the action at New York City's 15th Precinct is as hectic as ever. While Lieutenant Fancy continues as precinct commander, Detective Andy Sipowicz, although still a bit rough around the edges, has mellowed with the birth of his son. Detective Bobby Simone and Detective Diane Russell take the next step in their relationship, James Martinez becomes the Squad Delegate, and Greg Meadavoy considers becoming a surrogate father. But one thing that hasn't changed is the squad's determination to make sure the bad guys get their day in court and to also attempt to maintain a touch of normalcy in their personal lives even as they investigate cases that often put them directly in the line of fire.

在监狱里呆了20年后，安吉与她的老队员和儿子AJ重新团聚，现在他们是特种部队的一员；该队的第一项任务是潜入医院，寻找法国大使皮尔卡丹的潜在杀手。

服务警界多年的探长洪爷（郑则仕），却因个性不羁，办事不依法则，未为上司赏识。随后，结识舞女嘉嘉（伍咏薇），触发了一段不可收拾的孽恋，并倾力替她还债，不料被洪妻发现，一怒之下将洪爷毕生积蓄拿走。从此，洪爷深受打击，且饱受同僚蹊落，同时面临失去嘉嘉，在多方面压力下，决与贼匪勾结，合谋诈骗富商巨款。 　　警方了解事态严重，遂派陈帮办（成龙）负责追查，惜无甚进展，与众手下相处难以融洽，大受精神困扰，惟有向心理医生Clarissa（潘玲玲）求助；除帮助他解除种种精神压力外，也逐渐改变其处事态度，并赢得众手足的信任，两人更情愫渐生。　　在中、港、台警方的通力合作下，终将洪爷围捕；陈帮办更拼命缉捕疑犯，经过双方斗智又斗力后，洪爷强行突围，惜在身负重伤下与嘉嘉同时丧生。事后，陈帮办既立了大功，亦得到患难知己Clarissa欣然答允，成了他的终身伴侣。

D.C. Rachel Bailey在辛迪加即曼彻斯特谋杀专案组工作9号工作。 工作时她是个优秀的警察，但是处理工作以外的事情她就玩不转了。我们看到她时，男友Nick Savage吃饭时当众把她甩了。男友说他要离开。Rachel狠揍了Nick两下，但是看得出她确实内心伤的很深，尤其是当她怀疑Nick有外遇的时候。Bailey最好的朋友Janet Scott当时也在那里，一如既往的在第二天全力投入到工作中。

DCI Gill Murray, DC Janet Scott, DC Rachel Bailey find themselves working alongside the formidable DCI Julie Dodson when two badly burned bodies are found in remote woodland.

两位女侦探，一位颇具慈母风范，另一位则在情感上不够成熟。她们以各自独特怪异的人生观，在侦破案件和处理个人生活时取得了不同程度的成功。

"With DCI Gill Murray in retirement, ever-ambitious Rachel (Suranne Jones) returns from her Vice secondment fired up and full of new ideas and initiatives. She’s gained valuable experience and really wants to make her mark as she returns to Syndicate 9’s Murder Squad. Exhilarated to step up to the plate, Rachel is exactly who Janet (Lesley Sharp) and the Squad need to move forward with a terrifying and sinister Internet crime investigation of epic scale and unrelenting horror. Using her Vice authorisation, Rachel accesses a disturbing world where people brag about committing murder and lay down the gauntlet for the next victim. A game of ruthless life or death daring develops, as Scott & Bailey investigate multiple killers with horrifying and everlasting consequences. They will be changed forever and the investigation will take a devastating toll on their private, professional and personal lives." The drama will be executive produced by Nicola Shindler (Happy Valley, Last Tango in Halifax, Banana, Cucumber) founder of the Red Production Company and produced by Michaela Eccleston, Red’s Head of Production. Suranne Jones, who conceived the idea for the drama with fellow actress Sally Lindsay, will also executive produce alongside Nicola. Sally Lindsay also returns to the drama playing Rachel’s sister Alison. 5-1 Rachel steps up to acting DI on a case that becomes more sinister than it first appeared.