The Great Xavio is an interactive fiction mystery. The main characters Dr. Todd and Hagerston also appear in traditional fiction I've written, but the Great Xavio is a separate adventure.
You play as Hagerston, a graduate stuent at the University of California Berkeley; Dr. Todd is your thesis adviser and general bane of your life.
The game is written using the Inform 6 system by Graham Nelson, and was entered in the 2004 Interactive Fiction contest, where it placed eleventh. Dr. Todd was a finalist for the Xyzzy award for best NPC.
I revised the game substantially based on reviews after the end of the competition period. Download the latest revision here.
You can find more information, including links to reviews, at the interactive fiction wiki.