Simon Kress, a presumably wealthy exotic pet owner, ventures to an unknown pet store and meets the owner, Jala Wo, who introduces him to a terrarium full of sandkings. These creatures are semi-sentient insects that build castles, engage in warfare against each other, and carve the face of their owner into their castles as a means of worshiping them. Kress adopts the sandkings and initially dotes on them by feeding them his own table scraps, thereby earning their love. After inviting friends to come over and watch the sandkings fight, Kress takes on a harder edge and adopts friends' suggestions to place dangerous creatures into the tank for the sandkings to fight. He also begins to starve them as a means of controlling their warfare and exerting power against them. An ex-lover, Cath, becomes distraught and tries to set the sandkings free. Kress kills her and allows the queen of the sandkings to devour her body. He kills numerous other acquaintances in the same way and is forced to run away as the queen becomes more self-aware and bent on his destruction. Kress is killed by sandkings that have grown to human-size and adopted his cruel face as their own.