Travelling at speeds close to that of light, spacemen lived at an accelerated pace. When one of the twin boys left the starship, he grew older while his twin in space barely aged. So the starship twin left the ship to find what happened to his brother who was aging away on earth.

Here are two early stories by the well known SF Author Robert Silverberg. The Happy Unfortunate was published first in Amazing Stories in 1957 and explores the angst caused when the human race reaches into space but at the cost of needing to breed a new species; specialized 'spacers' who can withstand the tremendous rigors of acceleration. The Hunted Heroes was published in Amazing stories a year earlier, in 1956. It is a futuristic story that holds great hope for the resilience of the human race after the war destroys most of the world.

When Roy Walton becomes the new director of the UN division of population control, after the director is assassinated, he becomes the most hated man in the world. Being Director involved him in not only population control, but a terra-forming project on Venus, and negotiations with aliens. Not only that, but some people were trying to kill him. To stay alive, he had to become The Master of Life and Death. Summary by Dale Grothman.