Rise of the Dead: A 5th Level Adventure for 5th Edition

There is a ruin north of the town of Grimhollow that was once a noble's estate, but has long since fallen into disrepair. In fact, all that remains of it is the basement. During a storm not too long ago, a group of travelers took refuge in the basement. While hunkered down, they discovered a hidden entrance to a massive underground library. As they explored it, they unknowingly released the undead within and they've been pouring out periodically ever since. As such, the town of Grimhollow has been dealing with these monsters each night ever since. Unless someone can stem the tide of undead, the town's defenses will eventually fail.