From the back of the adventure: "The Xanthi (a.k.a. "spacewhales"), one of the most beautiful and strange life forms of deep space, are going mad! For no apparent reason they are attacking the domed cities and astrofarms of the Greenbelt region with ravenous fury. What has transformed these peaceful beings into merciless destroyers? Space chases, gunfights and dark, evil plots await the heroes in this adventure among the asteroids."