Islands of Space

The Venusians proved to be a humanoid race of people who used telepathy for communication. Although they were similar to Earthmen, their blue blood and double thumbs made them enough different to have caused distrust and racial friction, had not both planets been drawn together in a common bond of defense by the passing of the Black Star. The Black Star, Nigra, was a dead, burned-out sun surrounded by a planetary system very much like our own. But these people had been forced to use their science to produce enough heat and light to stay alive in the cold, black depths of interstellar space. There was nothing evil or menacing in their attack on the Solar System; they simply wanted a star that gave off light and heat.