I found this in the New Release department of my local video store, and saw it was independent, and I wondered if I was willing to think for ninety minutes. Finally, I gave in and picked it up, and I must say, this was a great movie.There is an apparent bombing or fire (it's never actually verified) at a high-rise building in the city. Four business execs, Rachel, Will, Dan, and Joseph, are frustrated with the crowds at one exit of the floor, and find another that leads them down into the basement. An explosion of some sorts traps them in a fallout shelter, and they must learn to deal with each other for however long they're down there. Interestingly enough, all these characters are connected in some not so friendly ways. Rachel is a top exec who just had to fire Dan, whose job Will is getting, and Joseph is Dan's young protege. So, without a doubt, the tension is thick, and things get more and more intense, as the water supply becomes the only grasp on life, as well as a slow chiseling away at a sewer grate that may soon lead to their escape. Desperation takes over, as Rachel grows a close bond with Will, Joseph tries to independence himself from Dan, and Dan grows more and more mad, eventually becoming murderous. To reveal anymore would give away major plot pieces that have to be seen to be experienced.A great film, with a solid cast of new faces, who all look so real and act so believably, you really learn to connect with them. The ending is great. You hold your breath the whole way through the movie, and double-crossing is always a possibility. The ending itself leaves you with a weird feeling, and you start to think you're watching "Carnival of Souls," (don't worry, no spoiler in that) and some questions are left to your imagination. All in all, a great film, and worth seeing.