In Scarlet Flames

From the Wizards of the Coast website: Two Red Wizards of Thay have undertaken a secret mission into the High Moors east of the Sword Coast. They are searching for something or someone. Whatever their goal out there in the cold and windswept hills, if the Red Wizards want to keep it secret then it is probably best uncovered swiftly for the good of everyone else. Even the mercenaries who escorted them into the wilderness earlier agree: someone should stop them. Pursuing the Red Wizards leads the adventurers to a barrow mound in the wild grasses of the High Moors. At the barrow, they discover the remnants of a wizards' sanctum still being plundered. The fate of its lore and treasures is up to the characters. Without caution, things may get out of hand. This Dungeons & Dragons adventure is written to suit four to six characters of 8th level. With this text and the core D&D manuals, you have everything you need to play.