The dark, mute, ancient asteroid, a craggy and pitted super nova-forged behemoth more than fifteen kilometers across, spun slowly and silently in the near-void chill of space. Once there had been millions of similar drifting objects of various sizes, shapes, and compositions in the Solar System that included Earth, building blocks for planets and moons, but after many eons most that ventured relatively near the Sun were gone: combined with planets or with the Sun itself such that their identities were forever lost.
As this solitary wayfarer passed near the Sun countless thousands of times, lighter substances were boiled and blasted from it, further purifying it, until what remained after billions of years was nearly pure iron, plus a small percentage of nickel and traces of other heavy, resilient elements. Against all odds it had for more than four billion years avoided merging with larger bodies orbiting the Sun, though its orbit had been altered by them many times. Someday, it would fatally collide with a body larger than itself and lose its identity, but given its orbit, that day would not be soon.
Then the spacecraft came. It deposited three small objects on the rogue asteroid before withdrawing, objects that soon exploded with the hellish fury of nuclear fission, vaporizing and blasting away a tiny portion of the asteroid's great mass, and changing its orbit ever so slightly.
The spacecraft soon returned briefly to make measurements of the asteroid’s altered trajectory. After a few minute adjustments were made using the ship’s own thrusters, the asteroid’s final, deadly course was confirmed. The visitors left. The asteroid, alone once again, was now enlisted in a very ancient game, a conflict of dark, undying hate that even most of the pawns in the departing spaceship did not suspect.
Nor did the billions of Earth humans now menaced with near-term cataclysmic apocalypse yet realize their fate. Unsuspecting, they went on with their doomed, pointless lives.