After a bruising divorce, headstrong Juliet Miller invests in a flat and advertises for a flatmate, little believing that in her late thirties she'll find anyone suitable. But along comes self-employed copywriter Hattie, raw from her own relationship split, and the two woman hit it off. When Juliet's twin brother Guy meets Hattie, he is overcome with a massive crush. But being a shy, gentle giant, he communicates so clumsily with her as to give her the opposite impression.
Guy's best friend Steve has always had a secret, unrequited crush on Juliet. After a night of too much wine, Steve and Juliet end up in bed, after moaning about the lack of sex in their lives. Convinced that Juliet doesn't feel the same way, Steve agrees to a 'just-sex' relationship, until they can both find other partners.
Just when Guy has finally plucked up the courage to tell Hattie how he feels, she embarks on an internet relationship - which seems to tick all the boxes. Meanwhile she is growing closer to Guy's family. Reeling from her divorce, and a series of devastating miscarriages, Hattie has never had much love in her life and is obviously thirsty for affection. She loves the whole Miller family, from Juliet and Guy's warm, loving parents, to their ancient one-eyed black cat. But can Guy turn Hattie's affection for his family into something more - into love for him? And then Juliet makes a discovery, which will turn the lives of all four friends upside-down . . .