This map is still curently in BETA, but it has already had and update. Basically you work for a company named Crepho Inc. You test weapons for them, so you have to go through chambers and kill mobs. The storyline has a few twists, and I would really appreciate it if you checked it out! If you do a Let's Play of it, then I'll feature it on the minecraftforum page.

More info one the minecraftforum page (download link)
Thanks!