Ooo! This is great! I love stuff like this. It was short and sweet, simple and concise. But, the reader understands what's going on even without a whole lot of back story and build-up. I was still sucked in and dragged right along with Sam and Matt when it shifted from friendly bickering to zomgwtf.

And while I was left wanting to know what happened after the story ended, I don't feel cheated like I do a lot of the time when authors attempt to end it like this. With this story, I felt good being left to decide for myself what precisely what happens next.

Great job! :D