What's hidden inside Looper's time machine?

We keep getting more fascinating glimpses of Rian Johson's time-traveling gangster movie Looper. The latest clue: This strange poster, which only raises more questions. What's the time machine filled with? Books, journals, or something else? We don't know.

What we do know is that this movie stars Joseph Gordon-Levitt playing a younger version of Bruce Willis. JGL is a hit man, who has kill time travelers sent back in time from the year 2072 by his bosses (back to his time, in 2042). But when his older self appears on the killing floor, all bets are off. Hot damn, we can't wait for this flick to come out in September. And seriously, what's in the box?

What's hidden inside Looper's time machine?

[poster via IGN]