Would I feel it, I wondered, if there was a worm inside me? Surely I would—Ariana had felt it, although we had dismissed it as a hallucination. But I could not help but wonder if the parasite might be learning to hide itself better. It had learned to control a human body, to fly a human ship, to use human language. It had learned to withstand an electric shock. It might even now be biding its time inside me, weaving thin, grasping threads into the fibers of my spine.

A gleam of silver appeared between the woman’s fingers. The parasite wriggled from her corpse slowly, searchingly. On the thermal image display it was the same temperature as the air, utterly invisible, but the camera showed it clearly, bending this way and that, so slender and delicate, like a snake tasting its surroundings.

Suddenly, with a muffled roar, there was fire. It rolled from the far end of the chamber, swamping the thermal imaging. I had thought the parasite might twitch or whip back and forth, try to flee or escape, but even when the flames engulfed it, it scarcely seemed to notice. The metal glowed red-hot, then broke into red beads that pulled apart and disintegrated.

It was working. The fire was destroying the parasite.

We watched in silence. It seemed to take a very long time, to reduce what had been a human to a fine white ash, but according to the disposal unit, fewer than twenty minutes had passed.

Twenty minutes. Four hundred and seventy-seven bodies, and not all would be as easy to access and move as this one had been. And even if we could destroy every single body before SPEC arrived, we could not cleanse the blood from every surface. It was impossible. We could not make the ship safe. The parasite would find a way. The outbreak would begin anew on the Moon, or Earth, or Providence, wherever it found itself again in favorable conditions.