“虎度门”指粤剧里演员出场的台口，跨过虎度门，意味着全身心交予戏。冷剑心（萧芳芳 饰）是一代粤剧名伶，驰骋舞台三十载，粉丝簇拥众多，而今面对丈夫事业失败，想带全家移民澳洲，剑心要面临是否就此离开舞台的抉择。同时剑心也被家务事缠身，女儿竟然谈了个“女朋友”，就算她在台上反串生角，也难以接受这个事实。此时又恰逢剧团新晋小花旦叶玉霜（袁咏仪 饰），剑心看重她的潜质，又目睹她被养父打骂，起了怜惜之心收下她做干女儿，而从加拿大追着前来看望玉霜的小男友阿俊（陈晓东 饰），被证实是剑心当年在南洋的私生子，带出她当年为了舞台放弃抚养儿子的旧事…… 告别场演出，台下坐着并不知情的儿子，哽咽着无法上台的冷剑心，终于收下泪水踏出虎度门……Cross the Hu-du-men - the demarcation between the back and front stage in Cantonese opera, and you leave yourself behind to absorb totally in your character. Lang Kim-sum is a charismatic Cantonese opera star who understands perfectly it's a point of no return once she crosses the Hu-du-men on stage, and in life as well. Respected by colleagues and friends and about to retire, Lang has yet to face new, unexpected Hu-du-men's in domestic and professional life. Husband Chan suddenly wants to immigrate. Daughter Mimi has a lesbian relationship. At work, her progressive opera director causes havoc in reforming a traditional art. Lang's protege Ip Yuk-sheung chooses between career and love, and a secret of Lang's past also surfaces. Lang, the quintessential master of vicissitudes on stage and in life, braves new crises and dilemma with gentle and light-hearted flair.
