“ Arakis's zombie problem went largely ignored, because it was believed that the Shai-Hulud (sand worms) would effectively dispose of the undead walkers. Unfortunately the problem grew until the roving herds of sunburnt ghouls threatened the flow of spice. While observing one of the great reanimated masses over take a Harvester from the safety of an ornithopter, an Imperial Zoologists noted that the sand caked flesh eating revenants walked entirely without rhythm.
Shortly after receiving this report the Bene Gesserits claimed to have a solution to Arakis's hellish resurrections. They asserted to the agents of the great houses that the worms could be drawn to the walkers using an ancient sonic weapon. According to the sisters, exposing the zombies to an antediluvian ballad composed by the great master M. Jackson would force them to step in time.”
“ A casual remark by one of the party about something met on a previous adventure leads to a summons to and grilling by the Mages' Guild (or equivalent), probably resulting in an expedition back to that area to recover the things for study by the Guild. The party's presence will be 'requested' for this expedition.”