The Guildmaster's Museum

From the introduction: Kirik, an illusionist/assassin, has fallen under the control of an intelligent sword, Setep, fashioned and controlled by Anubis. The sword coerces Kirik to steal a sacred statue that is in the care of the party, and lead them to the Guildmaster's Museum. Publisher's blurb: A sacred statuette, given into the party's care, is stolen in Thinnes, their home city. The characters pursue the thief into an old building that used to be a testing ground for high level thieves. They must locate the thief and recover the statuette.