Professor's Study

Your proposal has been approved for a grant to research and lead an expedition to find a long forgotten relic from a lost civilization. You have recruited Professor Martin Alabaster, a world renowned historian, to help you. His previous research into the relic is well documented. Allowing him to continue that work, you hope it will aid in figuring out the location of the relic. As the weeks go by though you notice Alabaster becoming more and more paranoid until one day you get a very disturbing phone call from him. Racing to his home, you and your team enter to find the place a mess. Upon entering his study the door shuts and a recording is heard "I'm sorry but I can't take any chances, the wrong people might have arrived here first. A corrosive and colorless gas will destroy the room and all of it's content in one hour." A small note is on the desk that looks like a riddle. What happened to the Professor? Will you and your team find a way out of his study or will you succumb to the gas?