Ender Wiggin
1) Ender's game
3) Xenocide
The planet Lusitania is home to three sentient species: the Pequeninos, a large colony of humans, and the Hive Queen, who was brought there by Ender Wiggin. But now, once again, the human race has grown fearful; the Starways Congress has gathered a fleet to destroy Lusitania. Ender's oldest friend, Jane, an evolved computer intelligence, can save the three sentient species of Lusitania. She has learned how to move ships outside the universe, and
...Orson Scott Card's The Last Shadow is the long-awaited conclusion to both the original Ender series and the Ender's Shadow series, as the children of Ender and Bean solve the great problem of the Ender Universe—the deadly virus they call the descolada, which is incurable and will kill all of humanity if it is allowed to escape from Lusitania.
One planet.
Three sapient species living peacefully together.
And one deadly