Corpus Earthling

"Rocks: silent, inanimate objects torn from the Earth's ancient crust. Yielding up to man over the long centuries all that is known of the planet on which we live withholding from man forever their veiled secrets of the nature of matter and cosmic catastrophe, the secrets of other worlds in the vastness of the universe, of other forms of life, of strange organisms beyond the imagination of man."

[edit] Plot

Intelligent parasitic aliens with the intention of commandeering the human race take refuge in a geologist's laboratory disguised as rocks. Although undetected by ordinary humans, one doctor (with a surgically-implanted metal plate in his skull) is able to "hear" the aliens communicate with each other while they are discussing their plot. Although the doctor is unsure if what he hears is delusional or real, the aliens are convinced he is a threat to their plans and set out to kill him.

[edit] Closing narration

"Two black crystalline rocks: unclassifiable. Objects on the border between the living and the nonliving. A reminder of the thin line that separates the animate from the inanimate. Something to ponder on. Something to stay the hand when it reaches out innocently for the whitened pebble, the veined stone, the dead unmoving rocks of our planet."