Greg the Cop and Greg the Punk

Greg the Cop and Greg the Punk is two novellas about a guy named Greg. In the first one, Greg is a bigoted policeman, who, with the help of an old friend named Jinx (who just happens to have been dead for six months), rediscovers his past, and gets what he deserves. In Greg the Punk, he's a teenager in the distant future who wakes up in Jinx's room, and quickly finds himself a prisoner in a futuristic building full of people from other walks of life and times in history.