In C.S. Lewis’s The Silver Chair, Jill Pole’s school friend is Eustace Scrubb.
Jill and Eustace are pupils at the experimental boarding school attended by several characters in the Narnia series. After escaping from bullying at school, they reach Aslan’s country, where Aslan gives Jill a sequence of signs to remember and follow.
Their mission is to find Prince Rilian, the missing son of King Caspian X. The search takes them through Narnia and into the Underland, where they encounter the Lady of the Green Kirtle and a powerful enchantment.
Eustace first appears in The Voyage of the Dawn Treader, where he begins as a selfish and unpleasant boy before undergoing a famous transformation. He later returns as a more courageous character. Jill Pole, meanwhile, is introduced in The Silver Chair and does not belong to the Pevensie family.