It appeared in Isaac Asimov's Science Fiction Magazine in 1989, and was subsequently included in Card's collection Maps in a Mirror.
After a childhood accident where he was shot by a stray bullet while sleeping, the narrator of the story undergoes a unique transformation: 60% of his brain is replaced with artificial computer "goo".
Consequently, his thyroid glands cease to function, halting his physical development, leaving him trapped in the body of a child.
Posing as a baby sitter, the narrator gains access to the official's private life, using this insight to successfully crack the code.
Upon Dogwalker's return, it becomes clear that the criminal group made an example out of him, subjecting him to a transformation similar to the narrator's, but with his brain entirely replaced by the same computer "goo.".