Free The Rings of Tantalus by Edmund Cooper

Uhlmann have worked themselves into the deck analysing the samples. They have given me a lot of useful data; and, of course, when we are allowed outside, I’ll have a lot more. Do you want to go through the data with me, or should I just boil it down.”
    “Boil it down. It’s been a tiring day.”
    “O.K., Boss. It looks as though the biosphere of Tantalus is a natural paradise. The air is slightly richer in oxygen, and there is not the slightest trace of the Earth-type pollutants. Nobody has been fucking this planet about —and that’s for sure. The soil samples are a farmer’s dream—black prairie soil, rich in organic matter, non-saline, highly productive. We should be able to plough it up, toss in Earth seeds and jump back quickly so we won’t get hit when the crop shoots up.” Kwango gave a grim smile. “Be a long time before even greedy Earth men can turn this place into a dust-bowl. To sum up, it’s as near as dammit like the temperate and semi-tropical regions of Earth about a hundred thousand years before some fool Terran discovered the use of fire.”
    “In short, the jackpot?”
    “In short, the jackpot.”
    “Except, perhaps, for the rings.”
    “Except, perhaps, for the rings,” agreed Kwango. “But I’m not worrying too much. I have my theories about those rings… We had it rough on Kratos, Commander, but we licked the death worms.”
    Conrad gave a faint smile. “What you really meant to say was that you licked the death worms.”
    “With some slight assistance,” said Kwango generously.
    “Your kami-kaze attack on the queen provided some useful data.”
    Conrad ignored the provocation. “Tell me the Kwango explanation of the riddle of the rings.”
    Kwango looked pained. “Boss, it’s only a first scenario. I don’t like to commit myself until I have some more data.”
    “Commit yourself, Kurt. That is an order.”
    Kwango sighed. “You are a hard man to work fo*, Commander.”
    “I know. Spill.”
    “Well, they are not the work of intelligent indigenes.”
    “Why not?”
    “Because there ain’t no intelligent indigenes. Or if there were, they have all gone under the hill.”
    “Why do you say that?”
    “Orbital survey. No trace of nuclear power, no radio signals, no sign of electric power, no internal combustion engines, not even a puff of smoke from de ole steam engine. So, given the facts that we have one large moth-eaten derelict space vessel in eccentric orbit and that we also have a mute enigmatic ring system on Tantalus, the first Kwango scenario goes as follows: the space vessel brought an alien and intelligent life-form to Tantalus— probably for reasons similar to ours.
    “Surprise, surprise! They found somebody had got here before them. The rings have to have a function. If they were the work of indigenes, there would probably be other systems all over the planet. So they were built by exploration group one for some as yet unknown reason.”
    “If they were built by natives,” said Conrad, “they wouldn’t necessarily have to be all over the planet. Take Earth. There’s only one set of pyramids.”
    “Yes,” countered Kwango, “but there are other types of monument to human stupidity. Here on Tantalus, there is nothing but the ring system… So the first Kwango scenario maintains that group one didn’t give the big hello when group two arrived. Chances are, they blasted the starship before any of its crew could drop dirtside. What we have we hold, and all that crap. Not very nice people.”
    “So where are the descendants of group one?” demanded Conrad.
    “I don’t know, Boss,” said Kwango weakly. “Maybe the star-ship took them out while it was getting hammered… I need more data.”
    “You also need your head examined. The odds against two groups from different parts of the galaxy, presumably, hitting on this particular planet at the same time are greater than the odds against a monkey being able to pound out the U.N. Charter by randomly