It's based on the Thomas Pierce short story "Tardy Man" that was published in "The New Yorker" last year. Pierce will also write the script.
The dystopian story is about a group of people who have indestructible fire suits fused to their spines so they can recover objects for wealthy people whose houses go up in flames. The corporation they work for forbids them to veer from their salvage missions, even when other humans are in danger. Naturally, the lead character decides to deviate from her mission.
In the story, the main character is a man called Keith. It's not clear if Witherspoon will be playing a different character or if the script will gender-swap the lead.
Six studios reportedly were bidding for this package, with Sony Pictures among the finalists.