Shadow of the Giant picks up where the notably weaker effort Shadow Puppets left off. Happily the quality of this tale was back up to par with the other books in the series. At this point in the story Andrew "Ender" Wiggin has long since left on his journey to become the new governor of an Earth colony on a former world inhabited by the alien Formic species. On Earth, the children that were members of Ender's command group that defeated the Formics are heading up the leadership of the nations and the militaries that are vying for power. National alliances are formed and tested, all in a charged effort for overall supremacy. Europe and Asia are a powder keg with wars developing between the dominant armies of Russia, the Muslims, and the Chinese. Against this violent charge, Ender Wiggin's brother Peter, who has been elected as the Hegemon of Earth, is trying to unite the nations of the Earth into a single people, much as they were when they came together to deal with the Formic attack on Earth. However, Peter does not have large armies at his disposal. He has his wits, his sensibilities, and he has the genius Julian "Bean" Delphiki on his side, the child who had been groomed as Ender's alternate in the Formic wars.
The story really weaves a complex international tapestry that Card pulled off quite well. His characters behaved in accordance with their makeup and their beliefs. No corners were cut or legacies short circuited to bring the story to its crescendo and its conclusion. As the story ends, Peter has once again maneuvered his chess pieces such that the Earth is nearly fully united behind a single leader. Peter's true purpose, which has always been a bit of a mystery, finally comes into some focus. Since his childhood, he came across as deranged, selfish, and burning with jealousy over his brother Ender's success. Seemingly the pain from his childhood drove him to a desperate lust for power and attention. Yet as the story developed, Peter comes to meet his true potential and his motives are for the most part pure and selfless. At the end of the story, Peter gets a chance to talk with Ender on his colony-bound ship. This is a sweet and revealing moment.
The story ends with Bean taking some of his children and heading out into space to buy himself some time while the best scientists on the Earth search for a cure for the genetic defect that is killing him and will claim the children with him. This is the subject of the final part of the Shadow Saga, Shadows in Flight.