I have to be honest here, this is a ripoff. As I read it seemed to me you just interchanged the names from the movies, with the Buffyverse characters. It would have been a better read, had you taken the simple plot idea, being stuck in a building with terrorist/robbers, and then wrote around that but instead you pretty much did scene by scene and in alot of places word by word from the movie. I own the movie, so I can watch it whenever I want, this is a disappointment for me. And I would like to put this out there to all who write like this, this is not writing, this is not original, this is in essence copying. And I'll say the 'P' word it's quite plagarist, but I won't take issue with that since you're not copying any other author here, I'll leave that between you and Fox Studio, who I think owns the movie. I probably won't read anymore of this because as I've said I own the movie, and to be honest again it's better. I don't wish to sound mean, but I think it's best that you know this is not considered 'writing', and maybe next time if you're going to take a plot from a movie, just use the plot and write your own story around it.