 40, 80, 400 miles. It came to a stop and hung out there, waiting. Earthman Tommy Dort, climbing into his atomic-driven space suit inside the airlock, heard this mileage report and felt safer, but just a little bit safer. For if the unknown black space intruder had stopped its retreat at 400 miles, he reasoned it might not have weapons effective at a greater distance. But Tommy felt lonely and a little expendable.