"Walkers." she waits, chancing that they'll be a flicker of recognition in his eyes and when there isn't she carries on to explain.

"I think it was... three years ago?" She was eight, now she's eleven, Clem's fairly certain anyway. "Dead people, they started getting up, started eating anything that was alive. Mostly people. People who die turn into them." he can probably figure out the result of that himself but Clementine still adds, "There's not many people left."