At the beginning of the story, Caspian is going to find Aslan and ask him what to do about his successor, given that his son and heir has been missing for years. When Jill meets Aslan for the first time, he tells her that he has been calling her and Eustace since before they called to him, and he then gives her the mission of finding Prince Rilian. Aslan was planning the answer before Caspian had even asked the question!note Given that Aslan is meant to represent Jesus, Lewis may have intended this realization.
The Lady of the Green Kirtle's clothing, and later her appearance as the serpent, are described as "green as poison." This always seemed like an odd simile... until one remembers that arsenic was often used in the dyeing of (green) garments and wallpaper during Victorian times.
Genius Bonus: The "ettin" in Ettinsmoor is an archaic word for giant. Furthermore, it's derived from Proto-Germanic "etunaz" (giant), which seems to have been related to the Proto-Germanic "etaną" (to eat).
Puddleglum, the sort of person to speculate a snowstorm might appear in the middle of summer, is somehow the most optimistic of the whole group about Aslan. Whether through real snowstorms, narrow escapes from man-eating giants, or curses by a sorceress, he never lets his faith break, even willingly burning his foot to free himself and his friends from brainwashing. It may be surprising, until you realize he has the most reason to believe out of all of them. If Jill, Eustace, and Rilian were to be eternally enchanted by the Lady of the Green Kirtle, they would still be happy. Sure, they would feel some inexplicable emptiness inside, but remain able to find pleasure out of small things in the Underworld. Puddleglum, however, is severely depressive. If he were eternally enchanted by the Lady, he would have nothing left inside of him. He needs to believe the most in Aslan, otherwise he can't find happiness or meaning in anything.
Oddly enough, this manages to double as a Fridge Moment of Heartwarming. Aslan is able to provide even Puddleglum, a being who, by nature, can't escape seeing the worst in everything, with a reason to wake up every day.
