Psion by Joan D. Vinge.
The Twenty-Fifth Anniversary Edition of a Bestselling SF Classic.
Haunted…and hunted…. Tough half-breed Cat doesn’t need anyone, doesn’t trust anyone. On the streets of Oldcity, it’s better to be alone then to be burned, and Cat can take care of himself. However when he becomes caught in the web of an interstellar conspiracy, he finds that the plot hinges on one important tool – his mind.