The Avenger by Damon Knight

Peter Karson was dead. He had been dead for some time now, but the dark blood was still oozing from the crushed ruin of his face, trickling down into his sodden sleeve, and falling, drop by slow drop, from his fingertips. His head was tilted over the back of the chair at a queer, unnatural angle, so that the light made deep pools of shadow where his eyes had been.

There was no sound in the room except for the small splashing the blood made as it dropped into the sticky pool on the floor. The great banks of machinery around the walls were silent. I knew that they would never come to life again.

I rose and walked over to the window. Outside, the stars were as before: tiny, myriad points of light, infinitely far away. They had not changed, and yet they were suddenly no longer friendly. They were cold and alien. It was I who had changed: something inside me was dead, like the machinery, and like Peter.

It was a kind of indefinable emptiness. I do not think it was what Peter called an emotion; and yet it had nothing to do with logic, either. It was just an emptiness—a void that could not be filled by eating or drinking.

It was not a longing. I had no desire that things should be otherwise than they were. I did not even wish that Peter were not dead, for reason had told me that he had to die. That was the end of it.

But the void was still there, unexplainable and impossible to ignore. For the first time in all my life I had found a problem that I could not solve. Strange, disturbing sensations stirred and whispered within me, nagging, gnawing. And suddenly—something moved on the skin of my cheek. I raised a hand to it, slowly.

A tear was trickling down my cheek.