The planet Lusitania is home to three sentient species: the Pequeninos; a large colony of humans; and the Hive Queen, brought there by Ender. But once again the human race has grown fearful; Starways Congress has gathered a fleet to destroy Lusitania.
Jane, the evolved computer intelligence, can save the three sentient races of Lusitania. She has learned how to move ships outside the universe, and then instantly back to a different world, abolishing the light-speed limit. But it takes all the processing power available to her, and Starways Congress is shutting down the Net, world by world.
Soon Jane will not be able to move the ships. Ender's children must save her if they are to save themselves.
At the start of Children of the Mind, Jane was using her newly discovered abilities to take the Formics, humans and Pequeninos to distant habitable planets in order to colonize them, but she was losing her memories and concentration as the vast Ansible network was shut down. If she was to live, she must find a way to transfer her aiúa to a human body.
Andrew Wiggin's wife, Novinha, joined a religious order, the Children of the Mind of Christ, and Andrew insisted on joining it with her. His own aiúa was controlling his body, as well as Valentine Wiggin II and Peter Wiggin II, but his own body suffered as most of his attention was devoted to the efforts of Peter and Valentine, diverting much of the aiúa of his body into his other two. Peter, joined by Si Wang-mu, an intelligent servant girl from Path, went off to distant worlds attempting to manipulate the political arena to ultimately sway enough members of Starways Congress to vote against the destruction of Lusitania. Meanwhile, Miro Ribeira and Valentine II were spending all available time looking for additional habitable planets. Eventually it was revealed that they are in fact searching for the home planet of the aliens who created the devastating descolada virus. This planet was discovered and Miro dubbed the inhabitants Descoladores. However, the Lusitania Fleet was expected to arrive and destroy Lusitania within a few weeks. Jane was constantly shuttling shiploads of colonists off Lusitania and to the new colony worlds in an effort to get as many sentient beings off the planet as possible before it is destroyed.
Peter and Wang-mu traveled to the planets Divine Wind and Pacifica to convince the Japanese-led swing group of Starways Congress to revoke their order to destroy Lusitania. They succeeded, but the admiral at the head of the Lusitania Fleet disobeyed the order and did what he believed Ender Wiggin, the first Xenocide, would have done: he launched the Molecular Disruption Device to protect all human life from the (now harmless, though he didn't realize it) descolada, regardless of the political implications.
Jane was granted possession of Valentine Wiggin II's body, so she was not destroyed by the Ansible shutdown. She was then able to continue transporting starships instantaneously by putting part of her aiúa in the infinitely large network of Pequenino mothertrees. She got Peter and Wang-mu close enough to the M.D. Device so that she could transport the Molecular Disruption Device itself back to Lusitania Fleet's flagship, where it was then disarmed and disabled.
In the end, Andrew's aiúa left his old, original body and previous life behind to live in Peter Wiggin II's. Jane fell in love with Miro, and Peter with Si Wang-mu. Both couples got married under one of the Pequenino mothertrees, the same day as Andrew's funeral.
- "A worthy ending to what might be styled a saga of the ethical evolution of humanity, a concept seldom attempted before and never realized with the success Card achieves here."
- — Booklist
- Children of the Mind was once part of Xenocide, before it was split into two novels.