ROGUE by Sandy Schofield 

Welcome to the former penal colony of Charon, where a labyrinth of underground tunnels offer shelter to an Alien hive. Professor Ernst Kleist rules-a paranoid tyrant whose speciality is making humans disappear. Captain Joyce Palmer is bound for Charon. Only she and a few hand-picked Marines can stop Kleist in his tracks. Only they can stop the professor's most insane creation-the Rogue. 

THE LABYRINTH by S.D. Perry 

On the space station Innominata the infamous Dr Paul Church has built a maze of tunnels. Church is hiding the results of his latest experiments. His aim: to bring human and Alien together as one being. Colonel Dr Tony Crespi has one ambition-to work with Church. But one by one the men on Innominata have been dying in the attempt to meld Alien and man. When Crespi finds his way to the heart of the labyrinth he discovers a chamber of horrors-will he ever be able to find a way out?