Metal Like Blood in the Dark
ShortStory 7,180 words Recommended by 2 award/anthology sources
"Once upon a time there was a man who built two enormous machines, and he loved them very much. He called them Brother and Sister and programmed them with intelligences that woke and stretched and tested the limits of their metal bodies. When they did not like those limits, they altered them, nanite scurrying over nanite, tweaking the structure of their steel and carbon bones."
Content warnings 1
violence
Quasar links out; the story lives on Uncanny, where the author gets the click.