I am of the stars. I am called "forever". Eternity courses through my veins. It is cold beyond your sun where we come from. We seed the universe with the milk of a million moons. You are that seed. Your earth is our experiment. We vanquished the dinosaurs with the careless trajectory of a child's lost meteorite. We peopled your planet to experience your emotions - such feelings lost to us aeons ago. How we envied you your loves and passions, your dangerous desires.
The fires of your emotions gleamed like lost beacons in the darkened depths of the fathomless universe. And eight of you, plucked from Time. Not randomly, you understand. Representatives of your world's turbulent history. We have observed your tribulations from nameless nebulae.
The experiment is over. I am weary now. So tired. I too am far from home. Open the gate - complete the circle. You won't remember - you won't recall - for I am only the air that you breathe, after all...