"The Avenger" by Stuart Fleming is a science fiction novel that was published in the early 1940s. The story explores themes of human evolution and survival amid an alien invasion, concentrating on the concept of creating a new breed of humanity to combat superior extraterrestrial beings. The novel revolves around Peter Karson, a scientist who awakens from a coma to discover that Earth is under threat from invaders who possess horrifying abilities to fuse and harm humans. He creates a spaceship called "The Avenger" with the intent of sending himself into space to undergo mutative transformations to become a superman capable of fighting off the invaders. As he transforms and successfully breeds a new generation of intelligent beings, he faces the ethical dilemma of loyalty to his original humanity versus the kinship to the creatures he has created. The story culminates in a striking twist, revealing his creation's lack of emotional understanding and ultimate choice not to return to Earth, leading to a poignant conclusion about the nature of evolution and identity. (This is an automatically generated summary.)