Episode Stills: The Beginning in the End (Finale) 

Why did I look at these? I'm going to be thinking, "What do they mean? What do they mean? What do they mean?" until it airs.

The first two worry me, especially the second picture with Booth holding a letter (?). I keep thinking it's a letter of resignation for one of them.

Aaah! "Get rid of the horrible thoughts, mind. Just wait until it airs..." Like that's going to happen, haha.

I didn't think of it actually being a resignation letter but maybe you're right who knows.
My first thought was that it's a letter from the Army offering him that job that's suppose to be 'the opportunity'