A wounded Kim has been rescued by Hector, but they are stuck inside the planet's vast network of caves. Steve and Inge leave the expedition behind to look for them. All of them make their way through multiple, winding tunnels, trying to avoid particularly hostile and dangerous fauna in order to meet up. But the nightmare creatures aren't the only ones down there. A strange technology reveals itself, and the Iums come and go in large flocks. Soon, an alien yet hauntingly familiar sight will put Kim on the track of Betelgeuse's hidden secret...