Pierre Duval, a young editor, falls passionately in love with Manou. For a while it's total bliss. But Manou is behaving strangely and Pierre knows little or nothing about her. All he's sure of is that she's married to a certain Bernard Jaillac, a renowned engineer, with whom she's going to visit a construction site in Morrocco. Unable to live without her, Pierre manages to join the trip. Yet, there's a surprise in store for him. The woman travelling with the engineer isn't Manou, but Claire. Who is Claire? Who is Manou? To what intrigue has Pierre fallen victim?