You like pain? Torture? Trask stories? Then let me suggest Sue S. "Revisionist History". I believe she did a PG version for the archive - or you can find the nfic version at
www.annesplace.net It has all three of the above mentioned themes (and is extremely good - I should know, I was one of her betas)
Oh and I agree with Nancy. This idea sounds intriguing and someone should write it... just not me. I just finished a fanfic challenge that turned into a 137 pages... and my muse has left me to go on vacation.