It's a while since I read Rebecca, (third year at Uni, but that was only 2002-2003,) and at the time I was mostly reading coursebooks and theory books. I got The Scapegoat when I heard it was to be made into a TV drama this autumn. If they stick to the text it should be a really good dramatisation.
John, a university lecturer, is on holiday/fact gathering in France. He stops in Le Mans and there at a station buffet he meets Jean, a French Comte. They are strikingly similar, this chance likeness leads to them spending the evening together, drinking. When John wakes the next afternoon, Jean has taken his clothes, his car and his wallet, leaving John his clothes and belongings. A chauffeur is waiting to take Monsieur Le Comte back to the chateau.
Jean has left with John's identity and left John to pick up his life, and all it's attendant problems. John finds that he has to pass himself off as husband, son, father, brother, and lover to the circle of Jean's family. He does at first try to tell people that he is not Jean, but no-one believes him. But John has different values to Jean, he has always wanted family life, and finds that Jean's family life is an acrimonious one, where he, (Jean,) only cares for his own comfort, not John's way at all.
I know it sounds very confusing, but it isn't, as the errant Jean does not figure for most of the novel.
The novel does have an introduction which outlines the plot. I'm not sure if I like all aspects of this as it does reveal a few things, but it also lets the reader know that like Shakespeare, Du Maurier was fascinated by the possibility of duality, easiest explored by using twins or look-alikes.
I thoroughly enjoyed the novel and will be reading more of Du Maurier's in the future.