Exploring questions of guilt and responsibility, the second book in Thomas M. Disch's Supernatural Minnesota series, The M.D., is a satisfying mix of dark humor, biting social commentary, and terrifying horror. Given the power to heal or to harm by the Roman god Mercury through a magical staff, the caduceus, young Billy Michaels embarks on a lifelong journey of inflicting good and evil on those who cross his path. Wielding the caduceus, Billy, and later the grown-up, greedy physician William, can only cure in proportion to the amount of suffering he inflicts. From paralyzing his brother and mutilating schoolmates to wreaking a nationwide plague and running for-profit concentration camps for the sick, Michaels's powers spin quickly out of control.