M14: Tremor is a mission in Metroid Prime: Federation Force. In it, the Federation Force is deployed to Bion, tasked with uncovering the source of an underground disturbance in the planet's volcanic area. It does not take long for them to find it: Cyranon, a mechanism likely built by the ancient race of Bion. The mission's bonus objective is to destroy 20 Sentinels, serpentine mechanisms continuously spawned by Cyranon to defend itself. Fire Hoppers and an Omega Hopper can be found at the very beginning of the mission.