It showed a man in a bright red and yellow spacesuit standing at the bottom of an excavation and supporting a surveyor's rod marked off in tenths of a meter. It was obviously a night shot, and might have been taken anywhere on the Moon or Mars. But until now no planet had ever produced a scene like this.

The object before which the spacesuited man was posing was a vertical slab of jet-black material, about ten feet high and five feet wide: it reminded Floyd, somewhat ominously, of a giant tombstone. Perfectly sharp-edged and symmetrical, it was so black it seemed to have swallowed up the light falling upon it; there was no surface detail at all. It was impossible to tell whether it was made of stone or metal or plastic - or some material altogether unknown to man.

"TMA-1," Dr. Michaels declared, almost reverently. "It looks brand new, doesn't it? I can hardly blame those who thought it was just a few years old, and tried to connect it with the third Chinese Expedition, back in '98. But I never believed that - and now we've been able to date it positively, from local geological evidence.

"My colleagues and I, Dr. Floyd, will stake our reputations on this. TMA-l has nothing to do with the Chinese. Indeed, it has nothing to do with the human race - for when it was buried, there were no humans.