1950s London. Tom Knelston is charismatic, working class and driven by ambition, ideals and passion. He is a man to watch. His wife Alice shares his vision. It seems they are the perfect match.

Then out of the blue, Tom meets beautiful and unhappily married Diana Southcott, a fashion model. An exciting but dangerous affair is inevitable and potentially damaging to their careers. And when a child becomes ill, Tom is forced to make decisions about his principles, his reputation, his marriage, and most of all, his love for his child.