I only remember one specific part from the story. Dean had a lung injury, and stayed at Bobby's to head. Sam comes back from somewhere and freaks because Dean is outside working. Later Sam is informed that Dean's lung capacity is almost 100% when before it was something like 65%. I hope this sparks someone's memory because it's bugging the heck out of me that I KNOW this story, but can't remember the title. Thanks for any help.

FOUND