"The Doctor" is an exciting science fiction book from the famous writer Murray Leinster. In this book, readers go to the future, where the main character is a doctor who is looking for a way to save humanity from the threat of an external civilization. Delving into the book, readers will feel the tension and danger, and will be amazed by the complexity of the psychological characteristics of the characters. "The Doctor" is a story about wisdom, ingenuity and faith in salvation, which fascinates from the first lines and keeps you in suspense until the last page.