"Methuselah's Children" is a science fiction book by the famous author Robert Hines Hylenn. This book tells the story of a group of people who live on Earth, but have a special genetic gift - their age significantly exceeds the average human lifespan. The main character, Mary Sargent, finds a way to escape the persecution of government agencies in order to study her and her family's extended life. This book explores themes of eternity, human nature, and man's place in the larger cosmic dimension. Methuselah's Children is a fascinating science fiction that leaves the reader with many questions and thoughts to think about.