The Silver Chair is a Narnia story in which children Jill Pole and Eustace Scrubb are sent by Aslan to find the missing Prince Rilian. Accompanied by the marsh-wiggle Puddleglum, they journey through dangerous lands and the underground realm of the Underland to rescue the prince, who is being held captive and enchanted by the Lady of the Green Kirtle, a disguised witch. The story explores themes of courage, faith, and the importance of seeing through deception.