The adventurers entered the crypts, and quickly dispatched the goblins.
In the final goblin-infested chamber, after defeating a dire wolf, they found a locked and magically warded door, which resisted all attempts to force open.
They returned to Old Kellar, received their payment, and departed for Fallcrest, where they met the old wizard, Nimozaran the Green. He told them of the Old Baron of Harkenwold, who had tried to create an undead army almost 100 years ago. After transforming himself into a lich, the Baron was discovered by the other lords of the Nentir Vale, and locked into his catacombs. Then were the wards on the door created, along with seven Keystones, should the lich ever need to be accessed or released.
On their way out of the tower, they encountered the wizard’s apprentice, Merric Thistleton, who was just then dropped from his apprenticeship for his most recent misbehavior. He joined the party.