I have read everything in the posts above but I was hoping that Wesley of someone else could give me an up to date listing of source material for Hellnights in general and the Order of the Nail in particular. Also I know that The crimson throne adventure path has been mentioned as a source, I have flicked through it and can't find anything substantial, am I missing something?
Any hellp would be much appreciated :)
Try Council of Thieves, APs #27 and #28.
There's a recent PFS scenario about/with/against a Hellknight's order, too.
Ruyan.