On the first recon mission to Nilgocht, the Xeliopurge recons found nothing. However, a rock they took as a souvenier happened to be a spider egg. On their mission back to Vinheilm, the "rock" hatched. The startled recons crashed into an unknown planet; Malhalla.
The Vinheilmian Recon craft are made of a common mineral called Titanium. The craft left behind that unique metal on Malhalla, and has since become VERY valuable.
The eggs on the ship hatched and the spiders spread, and multiplied on the planet. They have since become mutated and recognized as a vital threat to The Grand Kingdom's safety.
One Xeliopurge survived and duplicated. Nobody knows where they reside today.