Helfire Mountain

From publisher blurb: For 4-6 Adventurers of Levels 7-9 A doomsday cult opened a portal within Helfire Mountain, unleashing an elemental lord upon the realm. There’s a chance of sending him back, however it requires access to the portal and the portal is well guarded. Helfire Mountain is part of 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.