What was this grey-y substance? My first thought was gunpowder, but it could be anything. And why was it in a trail, where did it lead to? And was it just me but did it look like there was metal on the ground (like a hatch) in shot, as in the powder was a diversion.
I think there must be some kind of DHARMA connection there. Could it lead back to another station? Why was Ben so insistent that they immediately move on?
Also, there's this smokey-chair thing people have been mentioning quite a lot. Essentially, there's a shot of Jacob's chair which has a little bit of a black shadow on, causing the theory that its the monster. I personally don't agree with it, but I'll let you all judge for yourselves (unfortunately I don't have cap of my own but I see that the meticulous DarkUFO does here :-D).
Tomorrow - full episode review, including why eye-liner Alpert was apparently born in his late 30s/early 40s and stayed that way.