Yes, they do. Only some of the other time travelers know that he is not really an Egyptian, everyone else is sure he is just Cheftu. And... you know, he is inhabiting that egyptian body since he's a teenager. And by now he considers himself more of an Egyptian than a French. Does that make any sense if you haven't read the book? ...Like, the female protagonist, Chloe, is so very much Chloe, and even though she is in an egyptian body as well in the first book, I wouldn't consider her an Egyptian. Cheftu on the other side is not Jean-Francois anymore, he's Cheftu, an Egyptian doctor.