In ‘Prometheus’, Dr Elizabeth Shaw chose to believe that an alien race with incredibly advanced technology created the human race on Earth. While doing so, they left a clue, to be deciphered by the humans, once they are intelligent enough, so that the humans they have “engineered” could go to the space and find them.
They did, and everything went to hell. Finally, Shaw realises that she was “...wrong, so wrong...” as she learns that the planet they have arrived is actually a “military installation” of the alien race, and they were working on a weapon of mass destruction in a cargo full of vases containing some goo-like substance (which in time would spawn those aliens as imagined by H R Giger). And, most importantly, they were on their way to the Earth with the cargo. But why? David the android explains: “To create something, you must destroy first...” So, the aliens wanted to destroy the human race. Why?