The three hitchhiked on a train carrying crates to the surface, inadvertently bringing Elita along. They eventually discovered a deactivated Trion and a mass grave of the Primes inside a cavern. After reactivating him, Trion revealed that Sentinel betrayed and murdered the Primes and allied with the Quintessons for power in return for Energon, and secretly removed the miners' transformation cogs to keep them powerless.