H.A. Swain is an American author best known for his science fiction and fantasy novels. He is the author of the popular "The Chronicles of Trentham" series, which follows the adventures of a group of adventurers in a post-apocalyptic world. He also wrote the "The Grendel Cycle" series, which follows a group of adventurers in a fantasy world. Swain's work is known for its vivid worldbuilding and imaginative characters.