In Half Moon Street, Paul Theroux brings us two brilliant short novels on the theme of a double life. Although they are worlds apart in scene and character, both are full of a kind of eerie menace that lies just beneath the outward events. Lauren Slaughter’s life began to change beyond recognition one evening at a dinner party where she met the quite strange Mr. Van Arkady. “There are five thousand people in the world,” he said, and he meant that literally. The other millions, he asserted, don’t really matter. Lauren, a Fellow at a respected institute and a student of the politics of the Persian Gulf, found a second, sinister life for herself when she met Captain Twilley and Madame Cybele and began to work for the Jasmine escort service. Doctor Slaughter is full of social satire and the promise of violence. It is a Rake’s Progress dazzlingly translated into a late-twentieth-century London. In Doctor DeMarr, Gerald DeMarr’s life suddenly changes one July day when his missing twin brother George turns up on the doorstep of their Massachusetts family home and demands to stay. Where has George been all these years? Before Gerald can find the answer, he discovers George dead of a drug overdose. Then, retracing his twin’s footsteps, he gradually reveals for himself a horrifying—and quite nearby—life that George has led and has tried to escape from. And, without willing it, Gerald is drawn into playing the role of his alter ego, and he plays it out to the terrible and unexpected ending.