Was actually pretty good. It didn't last as long as I would have preferred, but it worked anyway. I had my players trapped in a small temple in an abandoned village. The temple was still consecrated which is the only thing keeping the undead out. But the skeletons and zombies outside kept trying to get in. It made for a very tense scene. Of course when the undead (with a little help) were able to desecrate the temple they began to break in. We left the game with dawn an hour away and the front door of the temple breached.
All in all I think it went pretty well.