Ghosts of Dragonspear Castle

"In Ghosts of Dragonspear Castle, adventurers clash with a grave threat to the Sword Coast. Backed by Sir Isteval, a hero of yesteryear, they descend into dungeons to keep the secrets of an ancient elemental cult from falling into the clutches of the Red Wizards of Thay. Along the way, the adventurers face an immortal foe from Isteval's past, leading to an epic confrontation in the ruins of Dragonspear Castle.

Ghosts of Dragonspear Castle contains four adventures that connect to form a FORGOTTEN REALMS mini campaign, taking characters from level 1 to 10. This book also includes all the D&D Next rules a Dungeon Master needs to run the campaign, including monsters, spells, and magic items. Six pregenerated characters are included, or players can create their own characters using the rules downloadable for free. at www.dndnext.com"

Summary
A group of Red Wizards of Thay have constructed a base that contains a quartet of netherese portals that each lead to powerful elemental nodes. In order to access the power of those nodes, they need the portal keys. A Red Wizard managed to acquire one of the keys by attacking the Floshin Estates but was caught and executed in Daggerford after he passed the key on to an agent.

Sir Isteval, a retired paladin from Cormyr, hires a group of adventurers to go on a series of quests that result in acquiring the remaining three keys, taking the group to locations such as the Lizard Marsh and Mount Illefarn before engaging in a climactic battle in the ruins of Dragonspear Castle with vengeful red wizards and the rakshasa who has been manipulating events.