I liked the story for most of its length, it had a good build up of tension towards the inevitable ending. But, perhaps because I anticipated it, I had an issue with the ending. The whole story is about Claire's dread and discomfort and Ben was a side character. Then, at the end, the twist is that Claire is swapped for a pod person off-screen, and Ben is made out to be the victim.
But, well, he had the words "victim" written on him in glowing letters throughout. I was interested in Claire - what made her change from a loving, if damaged, mother and wife, to a murderer and cannibal who will inflict the same pain of her son that her father inflicted upon her? Apparently, it was just sudden personality-altering magic.
I think the ending belongs to a different story - it is the ending to a story told from Ben's perspective, where Claire is slowly becoming more and more distant until he discovers she changed way more than he thought. It's not the ending to the story we heard, where we were allowed into Claire's mind and no mystery remained for us there. It's a good ending, and a good buildup, but I don't think they entirely work together.