Bothorion. a lush wet world, is largely uninhabited, though much of the world bears the ruins of a once prosperous Imperial society before the appalling loss of the world several milenia ago. Caught in a voracious warp storm the planet was rediscovered devoid of intelligent life upon its rediscovery and many now consider the world "haunted".
The Orks believed no such thing, but following their landing in the wide overgrown expanses, they found it did harbour unexpected beasts. Tyranids. Clearly the lead element of Hive Fleet Triton which had ravaged Libria V had now reached the Mabb Nebula. The Orks managed to hold on to their landing zone following wave after wave of alien attack, but were unable to pursue and hunt down the creatures in the vast forests of the northern hemisphere of Bothorion. The human workers on the planet, not usually ones to favour Imperial visits, urgently contacted the sector capital, informing the high command that not one but two alien invaders had been sighted on their world.