A collective parasite is feeding on local inhabitants, draining their energy and leaving them to die. The swarm is not discriminating on who or what it attacks. Be it man or beast, neither are safe.  Viranian time traveller Drake and his Earth friend Gillian find themselves in plenty of trouble on Uraami when they attempt to help.  To add to their problems, a rebel colony insists on making life difficult.  To complete his mission Drake must also engage the help of his friend Alex.