LF Charlie Trapped in Prison fic

[jinx-tiger.livejournal.com]

I don't remember if there was a pairing but for some reason Charlie is in a prison and due to a rock slide or snow storm is trapped there.  Don is trying to coordinate with people to get to him.  When they finally get to the prison they find the power out and Charlie supposedly trapped with prisoners.  When they find him he is teaching math by candlelight to these hardcore prisoners that are just sitting there actually learning and don't want to be interrupted. 
Thanks in advance!
FOUND: It's For a Good Cause on fanfiction.net.