Rich, well-educated, successful. Mark, Sara and their daughter Ana seem like a perfect family, until innocent Ana is rushed to hospital with liver failure after a drug overdose.

She needs a transplant. The parents volunteer as donors, but Sara is unsuitable, so Mark is chosen. Tests reveal that he has an incompatible blood type. He is not Ana’s father. Their marriage is ripped apart by the revelation of Sara’s secret. Yet they must still save Ana.

In another town, poor immigrant Goran finalises plans to move his family back to his home country. Then one morning, Sara, a woman he has long forgotten, knocks on his door. She tells him he has a daughter and that the daughter will die unless he gives her a part of his liver. Mark, her husband, offers Goran money.

Sara, Mark, Goran, his wife Maria. Each must deal with the bombshell that has been thrown into their lives. Sara, to come to terms with a choice she made long ago for security over love; Mark, to overcome the loss and betrayal, and find again his love for his family; Goran, to risk his own life and the security of his family to save a daughter he never knew about; Maria, to let him go. Time is short.

I enjoy stories about extreme but realistic situations, with characters facing dilemmas full of strong, basic emotion - guilt, pride, shame, fear, desire - travelling intense paths, sympathetic, believable, but also unpredictable.

I was delighted to find that Any Use of You, the novel I was asked to adapt, contains the elements for such a story. In my adaptation the set-up remains close to the novel, but I have taken some freedom in my development to open the story out, from a tale with a single point of view, focused largely through flashbacks, into a multi-perspective one with greater dramatic conflict between different characters in the present.

I have tried to create the right balance of realism, intensity and unpredictability by building up characters who are ripe for conflict and change from the story’s beginning, but about whose complex, conflicting, and evolving motivations we gradually learn more. We learn, for example, that Sara had an affair. Later we learn that she truly loved the man and only stayed with her husband out of desire for security. Later still, we learn that she still loves the man fifteen years later... or believes she does. This in turn affects the forward movement of the story, because her husband Mark learns these details as we do, and the discoveries send him in new directions.

The story offers some heart-stopping emotional set-pieces: a man finds out he is not his daughter’s father; another man opens the door to a woman he loved many years ago, she tells him he has a daughter, and asks him to risk his life to save hers; I try to anchor the story in the concrete, realistic details of these and other similarly powerful scenes, in order to draw the audience into sharing the characters’ powerful emotions.

Thematically, I am fascinated by the conflict at work in the story between the cultural and the animal: on one side, the rational self, the contract of marriage, family, wealth, the social hierarchy; on the other, the body, its passions, demands, joys and weaknesses. I have tried to portray a range of personal and social dimensions of this conflict, without making didactic judgements about them.