The Demon's Gambit

From publisher blurb: A Swords & Wizardry Mini-Dungeon For 4-6 Adventurers of Levels 8-10 Respectable city merchants begin acting strange after visiting the Gnome and Feather, a newly reopened tavern. When friends and family of the merchants begin to disappear it draws the attention of the city guard. The Demon’s Gambit is eighth in a series of mini-dungeons designed to drop into existing adventures or campaigns. Use them as side quests or a way of getting in a quick adventure when you’re short on time.