"The Transition of Ludvig Prinn" is a Trail of Cthulhu scenario set in Arkham on Halloween night in the 1930s. It is intended to be played Pulp-style by three to six Investigator characters of any occupation and can be completed in a single session.
While attending a Halloween party at Dean Howard's house, the Investigators hear a news report on the radio concerning Morgan Albert, a chemistry professor at MU, who is now an escaped mental patient from Arkham Sanitarium. Their host explains that the professor was recently committed for a nervous breakdown, after being found wandering near his home and raving about undead sorcerers. Suddenly, there is a strange noise outside and the dean opens the front door thinking it is trick-or-treaters. Instead, a zombie appears and quickly kills the man. It then turns towards the Investigators...