The M.D. can be paired loosely with Thomas Disch’s earlier moral story The Businessman: A Tale of Terror (1984) and with his more recent critical play The Cardinal Detoxes (1990). Both explore questions of guilt and responsibility, and both place fantastic events firmly in the realm of the everyday. The M.D. concerns the use and abuse of mystical powers by William Michaels and his increasingly complex relationship with the god Mercury. Throughout the novel, the power of the good cure is balanced with the evil of disease and death. Michaels’ task is to learn this lesson for the benefit of himself and the world.
Michaels is a seemingly good Catholic boy. His earliest encounters with Mercury imbue him with a sense of his own powers and the importance of his magical caduceus. In the bosom of his family, he casts spells that end tragically for him and those around him, clearly illustrating the bounds of his power and the control he needs to learn. The collapse of his family is also hastened by the accidental death of his father, Henry.
The plot then shifts eight years to Michaels’ thirteenth birthday, when he is adopted by Sondra Winckelmeyer, his real mother. Here, in his new state of manhood, he excels at school and communes with Mercury regularly, learning the delicate nature of the magical caduceus. In a magnanimous gesture, Michaels bestows perfect health on his family and his mother’s expected baby, but the gift backfires. His mother gives birth to a monster and, in a fit of depression, tries to kill the baby. Failing this, she kills herself. In his grief, her husband, Ben, kills the child and is sent to jail. The section ends with Michaels and his stepsister, Judith, conceiving a child. The collapse of his second family makes clear that Michaels is now outside all social groups.
The final part of the novel is set in 1999. Michaels has become an illustrious doctor, responsible for the AIDS vaccine and equally responsible for a new plague, ARVIDS. At this point, Michaels’ illegitimate son, Judge, begins to communicate with Mercury in his own quest for the caduceus. The final clash between father and son ends in Michaels’ boyhood home, where all are destroyed in a fire. The epilogue makes clear that Michaels’ legitimate son, Henry, will be heir and apprentice to Mercury.