Thennos

Thennos is a small world of the Sthenelus System, the home system of the Iron Hands, which it shares with Medusa. It is an Adeptus Mechanicus research world, held to be sovereign territory of the Mechanicus although it lies under the protection of the Iron Hands. Its thin atmosphere is laden with radioactive dust, and storm bands and the craters of ancient impacts cover much of its surface. A debris belt between the orbits of Raeon and Thennos is thought to be the remains of a planet destroyed during the Age of Strife. Some time before 460.M41, when its population rose in insurrection under corrupted members of the Mechanicus led by the so-called Prophet Alpha, the Iron Hands invaded the world in a campaign of extermination in which the young Kardan Stronos fought as a sergeant of Clan Garrsak.