The film begins in London in the present day. A cleaner (Shirley Henderson) sets the scene as she removes some stained sheets from a marital bed whilst ruminating wryly on the nature of dirt. A woman rushes angrily through the room. “She” (Joan Allen) is an American scientist of Northern-Irish descent - a molecular biologist, a woman of distinction and achievement. She flies high; constantly on the move, circling the globe: conferences, commissions. Because she grew up in a divided country she understands holy and civil war; but at home - the immaculate white house we first see her in - she lives also on her own private battleground; a marriage that has broken down beyond repair. Her betraying English husband (Sam Neill) is in politics. They try to keep up an appearance of togetherness for the sake of his career, but she feels like an exile in her own home.
That night, at a banquet, she meets a man, who sees her grief and makes her laugh. “He” (Simon Abkarian) is Lebanese. Once a doctor, he had to escape from Beirut and now works as a cook. Where he once picked shrapnel out of people’s bodies and cut flesh to save their lives, he now cuts the flesh of animals. He cuts it well, he cooks it well, but the memory of war is never far away. His work-mates in the noisy kitchens (Gary Lewis, Wil Johnson, Raymond Waring) taunt him about his background and his beliefs. He lives alone in a small flat, separated from his culture, his family and his homeland.
Both exiles, He and She begin a passionate affair that starts sweetly as a sanctuary for each of them, but gradually pushes them to the limits of who and what they are and challenges all their assumptions about sexuality and surrender, morality and ethics, about God and about love.
World events start to cast a long shadow over their intimacy. Eventually he decides to end the affair when he finds he can no longer tolerate the imbalance of worldly power in their relationship; the secrecy, the claustrophobia of her need (which at first excited him), the challenge that the affair poses to his identity. His belief in God, and in the world he left behind, begins to surface once more, and now seems higher than the call of love and sex. All that first attracted him to this blonde American-Irish professional woman now reminds him only of his humiliation and loss.
He pushes her away at the very moment that her marriage seems to have irretrievably broken down, increasing her sense of isolation. The sexual and spiritual affinity she had found in her snatched moments with this man suddenly seem like more than just an illicit affair. The relationship has become the most important part of her life. They have a blazing argument in which, for the first time, he seems to have all the power in his hands -- the power to say “no”. But as he rejects her, the deeper reasons for his anger and anguish gradually emerge; the pain and humiliation he experiences every day as a man from the Middle-East living in the West.
In the middle of their night-long argument in an echoing car-park, the woman is called away to her beloved aunt (Sheila Hancock), who lies comatose in a nursing home in Belfast. The aunt is an atheist and socialist whose dying regret is that she never visited Cuba. When the aunt eventually dies, the woman telephones her lover to try to persuade him to travel with her to Havana and give their relationship a last chance. But he has returned to Beirut -- for the first time in over a decade -- to attend the baptism of the first-born son of an old friend.
It seems that everything is over. Their world has split in two. With nothing left to lose, the woman leaves for Havana. In the eyes of those who know her - her husband, her closest female friend (Samantha Bond), and her god-daughter (Stephanie Leonidas), for whom she is a mentor and role model - she seems to have vanished.
Will her lover join her in Cuba or have their differences finally made a life together impossible? The tragedy of their separation becomes the sweetest of sorrows; absence brings them closer and closer. Can “No” ever become “Yes”?