EXCERPT :

“Radar reporting!” he said curtly. “The Plumie ship is heading for us. I’ll have relative velocity in ten seconds.”He heard the skipper swear. Ten seconds later the Doppler measurement became possible. It said the Plumie plunged toward the Niccola at miles per second. In half a minute it was tens of miles per second. There was no re-transmission of signals. The Plumie ship had found itself discovered.