The War Minstrels

Kate N. Shadow was the name empath Kayla John Reed took when she was forced to flee her home planet and join the crew of the Falstaff, a "merchant" spaceship that stretched the limits of legal shipping beyond the breaking point. But even the Falstaff could not remain a haven for much longer, not when the forces of magnate Pelleas Karlson and empathy Yates Keller were out to put an end to all the Free Traders who currently plied the spaceways.
Kate had nearly fallen victim to the Groupmind controlled by Yates in her last devastating encounter with this ruthless enemy. And with her own empathic talents greatly weakened as a result, she knew that she would need to draw on resources far beyond her own to help the rebel troops known as the War Minstrels in their bid to break Karlson's control of the spaceways. Kate's only hope lay in finding the Mindstar, a mindstone of legendary proportions which could give its successful wielder infinite power - or suck the very life out of anyone who tried to master it and failed...