天光（郭晋安 饰）是重案组的CID，为人刚直不阿黑白分明。在追查一宗连环杀人案时，发现疑凶竟是二十年前从父亲手上逃脱的犯人。天光父亲大河（许绍雄 饰）是一名资质平庸的警察，且粗心大意不思上进，不仅让罪犯逃走，更是死在妓女床上，让天光母子蒙受巨大屈辱。以写作实况小说知名的作家高珊（陈慧珊 饰）此次亦追踪着天光手上的案件，二人对案件的不同理解造成摩擦，纷纷竞逐真相。 一日，天光发现父亲的旧电话神奇响起，对方声称自己是警察，只是所说所讲都停留在八十年代。细问起才发现那竟是二十年前的父亲大河！二人合作无间，跨越两个时空，共同追查真凶。
夜间新闻节目《新闻大门》的新闻编辑部迎来新人户山纱矢（佐佐木舞香 饰），她因祖母的喜好而误打误撞进入新闻行业。在节目改版的混乱中，遇见了志向成为记者却迷茫的入社两年目AD本桥悠介（道枝骏佑 饰），两人因一句话逐渐拉近距离，发展出“秘密关系”。与此同时，温柔体贴的同事宰善（金武俊 饰）也默默守护着纱矢。围绕三人展开的青春×梦想×悸动的职场爱情喜剧由此上演。
产科医生王甫芬（张家辉 饰）天资聪慧，但又傲慢自负，对于女友死在他怀中，而自己却束手无策他始终心存愧疚。八年前，他与心内科医生齐百恒（林峯 饰）一块远赴非洲执行援外仼务，亲眼目睹了人类在大自然中生存的韧性，援外的八年中，他的人生观发生了巨大改变。回港后，他不再为名利所累，一切以病人为中心，在慈善家的资助下，开设了龙城医疗中心，专心致志为病人服务。百恒初入龙城，他十分惊诧甫芬的工作作风，甫芬为病人治疗不惧踏医学雷区，不按常理出牌，但往往效果出人意料的好，久而久之，近朱者赤，百恒被其人道主义精神所感染，更被甫芬“即医病又医心” 的品德所感动......
Big Mood is a vivacious and rebellious portrayal of female friendship when infiltrated by the complexities of a serious mental illness. The six-part series will explore the messy pitfalls and idiosyncrasies of navigating adulthood through wicked humour, daft anecdotes, and unsettling truths. Best friends Maggie and Eddie have lived in each other’s pockets for ten years, through thick, thin, and multiple challenging eyebrow trends. But with the rest of their lives looming, careers hanging in the balance, and Maggie’s bipolar disorder making an unwelcome return to form, Eddie begins to question whether this friendship is really in their best interests. It’s a pivotal point in both their lives, bringing to the surface those all-important questions – could sleeping with your former History teacher be the key to happiness? Is a basement Rat Hotel a functional alternative to pest control? How do you stop your new psychiatrist giving you worry dolls? With their twenties behind them, Maggie and Eddie’s relationship faces the future – can it survive?
When a boat carrying illegal passengers is found crashed in the Thames, the team investigate.
