"Man Alone" by Don Berry is a science fiction novel written in the late 1950s. The story revolves around Colonel Richard Harkins, an astronaut who returns to Earth aboard the ship "Phoenix I", only to experience a profound psychological crisis that leads him to become isolated from reality and the people around him. The narrative explores themes of human disconnection and the psychological impact of space travel. The plot unfolds as Harkins, after a successful return from his mission, finds himself unable to engage with the people at Gila Base IV. He exhibits signs of distress, broadcasting an automatic distress signal and showing aversion to human interaction. Harkins becomes blind and deaf to the presence of others, plagued by a debilitating headache, and is haunted by invisible entities. The military and a psychiatrist, Colin Meany, work together to understand Harkins' condition, ultimately trying to reach him through memories of his wife, Martha. The narrative culminates in Harkins feeling overwhelmed by the enormity of space, leading to a tragic ending that highlights the profound loneliness of human existence when faced with the vastness of the universe. (This is an automatically generated summary.)