Bean, the main character in the book, also known as Julian Delphiki, is an orphan in Rotterdam. He survives on the street despite the odds against him. His brilliant mind, miles beyond anyone else's brings him to the attention of the Battle School. This story takes him through Bean's experiences in Battle School and shows how Bean, though seemingly peripheral in "Ender's Game" was much more important to the war, Battle School, and largely to the fate of Earth, than he seemed. The book reveals important insights and discoveries including Petra's explantation of her "betrayal" and how Dragon Army was chosen.
Ender's Shadow is the first of a series that includes Shadow of the Hegemon, Shadow Puppets, and a yet-to-be-published book called Shadow of the Giant.