In season 3 Belle is struggling with not only being Belle and Hannah but also with being a successful published author. She needs her clients to provide her with material for her new book so we see her have all sorts of experiences in the quest for ‘good material.’ Juggling three personas is hard enough, but when her sister Jackie arrives to stay out of the blue (her husband has had an affair) Belle’s life just gets even more complicated. We also introduce a new character – Duncan – Belle’s publisher. Duncan appears to be the archetypal English man – intelligent, restrained, mature – and Belle becomes very attracted to him. She believes this is a relationship which may work – after all, he knows all there is to know about her. But does she know all there is to know about Duncan?

《应召女郎的秘密日记》根据英国伦敦一名自称为《白日美人(Belle de Jour)》的性工作者的热门网络日记改编。
应召女郎Belle（比莉·派佩 Billie Piper 饰）原名Hannah，平日，在朋友和家人面前，她是穿着牛仔裤和T恤，与别人毫无差异的邻家女孩。而当夜晚来临，她从衣柜里拿出性感的衣服，换上别致的装束，为不同的男人提供“专业服务”。她的生活充满着矛盾的两面——作为一个女孩，她贴心，开朗，性格外向；而作为一名应召女郎，她专业，高档，却又不动情感。她小心翼翼又貌似游刃有余地平衡着生活中这两面，甚至连她最好的朋友都不知道她真实的工作……
终有一天，秘密被揭开，真实暴露出来，平衡被打破。而Hannah，又要怎样面对生活和情感的波折？