"The Silver Chair" will not be a continuation of the current series but rather the start of a new franchise. "The Silver Chair" picks up decades after "The Voyage of the Dawn Treader" in Narnia but less than a year later in England. King Caspian X, now an old man, enlists Aslan the lion to help find his missing son. Aslan sends two children from an English boarding school, Eustace Scrubb and Jill Pole, to track down the prince and solve the mystery.