本剧由四宗发生在香港，扣人心弦的真实刑案，带出四个令人惊惧的罪行。藉由一队重案组的警探办案实录贯穿而成，包括耸人听闻的「屯门色魔强奸案」，喧腾一时的桃色纠纷「溶尸案」，使市民提心吊胆的「大圈仔军火械劫案」，及「淫业大厦扫黄行动」案件，生动地描绘各阶层犯罪的人性丑恶。而编剧为了加强剧中人物与案件的关连性，特别穿插男女主角CID张兆军（林嘉华）、女CID丁兰（蓝洁瑛）、重案组总督察方伟（陶大宇）、扫黄组女总督察刘婉仪（梁婉静）及聂志华（张国强）一段微妙的五角感情关系，交错编织成属于都市人性化的实录档案。
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?
