You nailed it!
In this one, Sam and Dean don’t escape from their captivity like they did in BC– at least, not as fast as they did in BC. They remain trapped long enough to be branded and their training begun, prepping them for sale. It’s during an escape attempt gone wrong that the well-meaning doctor-in-training stumbles over them, finding two children where he thought two tiny dolls were lying abandoned on the sidewalk.
Sneak peek coming shortly!