[ WP ] A commonly thrown out material today is incredibly valuable and rare forty years from now .

We were unaware of how much they would want it. 
 
 We still do n't know where they came from. Language, and their lack there of, has proved a barrier to understanding more about The Visitors. Fortunately, the law of supply and demand is still intergalactically understood. 
 
 Earth's unique positioning and size create resources that are few and far between in the rest of the universe, and, to what we thought was our great fortune, we control the supply. 
 
 By the time they showed up most of it was gone, or at least hard to access. Rivers ran black. Filtration plants were never found more than 50 miles apart in highly populated areas. An ocean breeze was now something one would go well out of their way to avoid. 
 
 Initially The Visitors tried to take it by force. They dropped lines into any water bed they could find and began draining. We tried to stop them, but we quickly learned that any species that could manage intergalactic travel would have no issue crushing a still infantile civilization. 
 
 They stopped siphoning within weeks of arriving and their ships began to tap into our filtration systems. We quickly realized they needed it to be completely pure but were unsure why they did n't just do it themselves. That was the least of our worries though, supplies were running low and we could n't stop the draining. 
 
 It was only when an arc finally went down that we realized the potential for a business partnership with the Visitors. The cracked hull of the alien ship landed in Central Park New York, and, when it was opened it revealed an empty tank, which had no filtration or decontaminating abilities. We assume they did not expect us to contaminate the source of life on the planet and were ill equipped to deal with the surprising levels of shortsightedness displayed by our species. More importantly: Upon further inspection we also saw that silver and gold composed most of the ships hull and inner linings. 
 
 The speed at which we stripped the ship of all valuable metals is the most crucial piece of communication we have ever had with the Visitors. We reached a mutual understanding for a while, creating new filtration stations which made it easier for them to gather, filtering to higher purity than we were before and generally making their lives easier. In return our vaults and homes were filled with gold and silver that was dropped from slabs in the sky. 
 
 But as things improve so must they depreciate. The influx of gold into the economy dropped its value to the point where aluminum became more valuable. Without the monetary incentive, and forgetting the formidable power which these beings possessed, we began to stop filtering the water for them. 
 
 The Visitors dealt with the insubordination quickly and with vigour. Entire cities were wiped out in minutes; within a week civilization was no more. They then turned on the taps and learned to replicate the technology, and they currently drain enough water to dry out the earth inside of a decade. 
 
 There is hope. We had n't realized why they did n't come to the surface before hand. They are slow. Small. Weak. It's as if they are turtles without shells. They carry no weapons, relying on their ships to take us out in large numbers. The few of us that are left can fight them, evading their airstrikes and attacks.
