Knights of the Black Earth — Margaret Weis; Don Perrin

MAG FORCE 7

They are the finest mercenary squad in the known universe, agents who carry out missions too hot for anyone else to handle. No one can stand against them and nothing can divide them--except their leader, Xris, who is on a mission of vengeance against the comrade who betrayed him years before and left him to be transformed into a cyborg. Now at last the traitor is within his reach. Yet before Xris can claim his revenge, he and his men are recruited for a job they cannot turn down. For the Knights of the Black Earth have obtained the one weapon which can strike at the very heart of the galactic government. And Xris's only hope of stopping them lies in joining forces with an old enemy....