In the summer of 1963, François Mitterrand was going through a deep existential crisis. His political career was at a standstill and, after 19 years of marriage, the couple had grown apart. It was at this point that François Mitterrand met the woman who was to give new meaning to his life. Anne Pingeot, aged 19, was to become the companion of a lifetime, a woman who would be with him throughout his rise to power and who would remain by his side until his last breath. For the first time, Anne Pingeot has agreed to allow the fragments of this passionate love story — hundreds of letters and a diary — to be shown on television, before being donated to the National Library.

A couple has found peace in a strange manor by the sea but, on a hot evening, a visitor comes, troubling their solitude. However, three is not actually a crowd and they start start talking, exchanging points of view about philosophy, sociology and politics, eroticism as well.