The Plains of Eidolon stretch beyond Cetus, the last Ostron city, occupied by Grineer drilling stations excavating technology from the Old War. Ostron-assigned missions keep the daytime busy, but the enemy grows more dangerous the further into the Plains one ventures. At night the calculus changes entirely: towering Spectral Sentients called Eidolons rise from the waters and wander the landscape, accompanied by deadly Sentient drones. Only coordinated squads of Eidolon Hunters stand any chance of bringing them down.