'It shouldn't have been there. Nothing at all should have been there, save for the sparse drift of hydrogen atoms that did nothing at all to itigate the hard vacuum of interstellar space, and save for the Courier Adder, proceeding on her lawful occasions. It shouldn't have been there but it was, and Grimes and his officers were pleased rather than othwerwise that something had happened to break the monotony of the long voyage...' (Bertram Chandler)

What was there that shouldn't have been is a sphere... an emisary of the old ones that had probably malfuntioned eons ago while on its missionary voyage. When Grimes and his psionic officer Spooki Deane investigate their curiosity almost costs them their lives.