Vault of the Dracolich (5e)
Deep in the forest of Cormanthor lies the hoard of the dracolich Dretchroyaster¸ the prize of which is a diamond staff rumored to unlock the secrets of an ancient elven kingdom. The sage Imani is seeking dozens of adventurers to launch an all-out assault on the undead dragon's lair. The dracolich is a powerful foe - too great for even several parties to conquer - so it's going to take all of the heroes' courage¸ cunning¸ and speed to survive the dracolich's deadly vault.