Cliffside Manor: The World's Coziest Haunted Hotel

An ancient evil lurking in the basement of the Cliffside Manor taints the land. It turns pets and farm animals into hunters, and brings out the dark side in us all. What secrets are being hidden by the genteel hotel owner and the hotel's ghostly inhabitant?
Before they were epic heroes, they were regular people like you and I. This adventure will make heroes out of them. Characters begin without the benefit of weapons, rare items, or spells any higher than cantrips. As they explore, they will learn first level spells and find the items, armor, and weapons that each player wants for their character. It is essentially a Level 0 game.
The game includes five floors to explore, with four new undead, two new creature templates, and one new magic ring. There is enough material for one night's worth of adventuring. It's based on 3.5 edition rules, but can be easily adapted to any gaming system.