This story won the 1967 Hugo Award.
I cannot tell you how brilliant, and how deeply disturbing, this post-apocalyptic horror story is. I imagine it strongly influenced Clive Barker in his mastery of body-horror.
What can I tell you that won’t ruin the plot? I guess I can say that in a post-apocalyptic future, a small group of human survivors are at the mercy of a demented artificially intelligent computer who hates them. In many ways, I think it’s the natural, 20th century outgrowth of the same issues pondered in Frankenstein.
Just read it. But don’t do it right before you go to sleep (trust me, this was a bad plan.)