Speaker for the Dead

Speaker for the Dead, the second novel in Orson Scott Card's The Ender Saga, is the winner of the 1986 Nebula Award for Best Novel and the 1987 Hugo Award for Best Novel.
In the aftermath of his terrible war, Ender Wiggin disappeared, and a powerful voice arose: The Speaker for the Dead, who told the true story of the Bugger War.
Now, long years later, a second alien race has been discovered, but again the aliens' ways are strange and frightening...again, humans die. And it is only the Speaker for the Dead, who is also Ender Wiggin the Xenocide, who has the courage to confront the mystery...and the truth.
THE ENDER UNIVERSE
Ender series
Ender's Game / Ender in Exile / Speaker for the Dead / Xenocide / Children of the Mind
Ender's Shadow series
Ender's Shadow / Shadow of the Hegemon / Shadow Puppets / Shadow of the Giant / Shadows in Flight
Children of the Fleet
The First Formic War (with Aaron Johnston)
Earth Unaware / Earth Afire / Earth Awakens
The Second Formic War (with Aaron Johnston)
The Swarm /The Hive
Ender novellas
A War of Gifts /First Meetings