The first words, apparently, in the upcoming The Last Jedi are "Who are you?", spoken by Luke Skywalker to the enigmatic Rey.
Good question! When we saw The Force Awakens, I wondered whether young Rey might be one of the Kenobi clan, assuming that there are some holes in that family story. Then I came across this wrap-up of quite a lot of threads of Star Wars lore, making the case for exactly that. Have a look.