The Shards of the Gate of Darkness, Part 1

I thought the interrogation of the tiefling went really well. The first thing he said when questioned, in "Supernal", was "Speak to me in the language of my revered ancestors or do not speak to me at all." I spoke in made-up-on-the-fly "Supernal" through the entire scene, except for a few in-character comments in English/Common to insult the non-tiefling party members and remind them that he was only speaking a language they didn't understand in order to be an ass. I managed to use a few words I'd memorized beforehand - "ah" was always used for "I" or "me", and "p'tah" was the word for gnomes. I tried to make "Supernal" sound like less forceful klingon with more devilish hissing. For example, I derived "p'tah" from the klingon petaQ for "Useless garbage or incompetent person" - it seemed appropriate for what the tieflings thought of the gnomes.

Anyway, the tiefling revealed that his cabal was seeking to restore the ancient empire of Bael Turath to its former glory. They were also interested in obtaining the book the gnomes had been after back at the library (though it looks like I neglected to mention that bit in the log post). He said he had led the gnomes to the book, figuring he could kill them and take it once they obtained it. He then became uncooperative and burst his bonds with a balefire burst centered on himself. The party swiftly dispatched him, then headed to the library to make sure the book was safe.

When they reached the library, they smelled death and found zombies inside. A tiefling and one librarian were trying to extract information from another, bound, librarian. The eladrin warlord pulled a slick maneuver, fey stepping around the last zombie to get next to the ranged-attack tiefling. The group made short work of the zombies but had some trouble pinning down the teleporting tiefling.

Analysis:
I think they're getting irritated at the tiefling heretic's Cloak of Escape ability, but I don't think I had them fearing for their lives at any point during this fight.

They interrogated both librarians, but didn't learn much. They then sought out the head librarian at his home to let him know what was going on. He told them that the book everyone was after had been hidden away for safekeeping after the gnomes tried to get it. The party related what little information they had gotten from their various prisoners. The librarian said he would consult the book and see if he could figure out what the cabal was up to. When the group returned the next morning to consult with him, they found him tied up, badly burned and beaten...