Guarding the Haunted House

I used to work as a courier, but I couldn't take any more abuse from my unscrupulous supervisor, so I quit. After a series of twists and turns in my job search, I happened to see a high-paying night-shift security guard position posted by a skyscraper. Delighted, I went there to apply. What I never expected was that the building was a gathering place for yin energy, and I would be treated as blood food for an evil spirit and prepared as a sacrifice to fill a tomb in the underworld...