Vin Runs Off, gets trapped in cave ins V/C fic

[ganjapanda]

I'm looking for a fic where Vin gets a letter postmarked from Tascosa, and instead of asking anyone to help him read it, assumes this means his luck has run out and takes off. The others knew he'd been acting weird, but not why, and there is no trace of him anywhere. Eventually they find out that Nettie briefly saw him, and when she tried to talk to him he raced off on Peso, trail seemingly disappearing when she followed. Somehow they figure out there was a cave-in in the direction he'd ridden off towards and find him. This is at a beginning of Chris and Vin getting together, and Chris is not happy when he finds out why Vin took off, but it has a happy ending.

I believe it may have had some d/s elements.

Thanks for any help