The Siege of Dome (Empyrion #2)

the long version

Traveller, debt-dodger, itinerant critic, and writer of history books nobody buys, Orion Treet is astounded to be invited to accompany a top-secret mission: to observe and document an extra-terrestrial colony on a newly discovered planet. But the paradise planet Treet and his companions are promised is a nightmare world locked in a death spiral of hate, fear, and death. The explorer’s arrival rekindles an impossibly ancient feud – and deadly conflict between two highly evolved civilizations. It is the struggle for the future of a world, a battle where there can be no spectators. Everyone must choose a side.