D&D - Elemental Evil : Princes of the Apocalypse

Called to serve Evil, four corrupt prophets have secretly increased their power through the powers of the Elemental Princes.

Each of these prophets has gathered a group of cultists and creatures to serve them and help them build four elemental temples, which are bound to be deadly to any adventurer who dares venture into them. The heroic factions will have to discover the true power of each prophet and put them out of action, before their power becomes uncontrollable.