Seventh Son (1987) is an alternate history fantasy book written by Orson Scott Card. It is the first book in Card's The Tales of Alvin Maker series about Alvin Miller, the seventh son of a seventh son. Seventh Son was nominated for both the Hugo Award for Best Novel and the World Fantasy Award. The idea that the seventh son of a seventh son may have special powers is common in folklore around the world.
Seventh sons have strong "knacks" (magical powers or skills), and seventh sons of seventh sons are both very rare and powerful. In fact, young Alvin appears to be the only one in the world. His powers make him the target of The Unmaker. After he recognizes Alvin's powers as those of a Maker, he attempts to kill Alvin.