Alison, a junior editor in a publishing house, falls obsessionally in love with an older man, James, seemingly out of reach on both social and religious grounds. He is a Cambridge-educated accountant who once aspired to be a priest, from a well-to-do, ultra-Catholic family; she a woman of modest means and background who has rarely set foot inside a church.
Against the odds, she wins his love, but after five years of marriage she finds herself compelled to live a double life, upholding 'truths' in public which privately she abhors. The strain of this deception, coupled with deep sadness at their failure to conceive a longed-for child, leads her into an affair. Lie piles on lie as she begins to see falsehood everywhere - in advertising and politics, even science and history and, above all, in the constraining religion of her husband and his family.
Yet she still loves James, and his faith is an essential part of him; his virtue and integrity the very qualities that first attracted her. Thus the discovery that even he is entangled in deception comes as a profound shock.