An egg that is sure to arouse the interest of the 'Big Man' up at the castle – something the rest of the Pinhoe clan, and Gammer in particular, doesn't want at all. They finally settle on Woods House, Gammer's old place, and Marianne, while showing Cat around, gives him an old egg from the attic, an egg with strong 'Don't Notice' spells placed on it. He also meets the man who was bootboy at the Castle when the current Chrestomanci was a lad, Jason, and helps him and his new wife choose a house. Meanwhile, up at the Castle, Cat acquires a horse.

Until recently, the Farleighs and the Pinhoes had been working together, but it seems that Gammer has started a war, and it'll be hard to keep their operations under wraps for long. She's sure that Gammer's the one sending plagues to the Farleighs, a related clan that also wishes to stay out of the sights of the 'Big Man'. Gammer, the head of the Pinhoe clan, has ostensibly gone mad, but Marianne doesn't believe that she's completely 'round the twist. And the Pinhoes certainly are guilty of that. They don't want the 'Big Man', or Chrestomanci, interfering, as he tends to do when people misuse magic. Marianne Pinhoe's family tries to keep their magic a secret. The Pinhoe Egg is set in our time, during the tenure of Christopher Chant, who is Chrestomanci in five of the seven books and is often called Chrestomanci as a personal name.

The Chrestomanci books are collectively named for a powerful enchanter and British government official in a world parallel to ours, who supervises the use of magic -or the Chrestomanci, an office that requires a powerful enchanter and is responsible for supervising. It revisits Chrestomanci Castle and the character of Cat Chant from her first Chrestomanci book, but also introduces the character of Marianne Pinhoe, who lives in the village near the castle and whose family practices a rather different sort of magic from any that Chrestomanci or his charges have encountered. It was the last published of the seven Chrestomanci books(1977 to 2006). The Pinhoe Egg is a children's fantasy novel by British author Diana Wynne Jones published by HarperCollins Children's Books in 2006.

The lives of christopher chant