The main portion of the "who done it" comes from just plain trying to peace together what's all going on in the first place. One character will let on accusations or observations about something, while other characters may have something seemingly unrelated going on with each other. At first, it's all just a jumble of seemingly unrelated things that are to convenient to not be more than coincidences but by the end it all ends up laying itself out in a rather believable fashion - even with some things still feeling a bit like more than coincidence. A strange thing happens between two sections, where a narrator elaborates on something that the movie was apparently too busy to show previously after not existing for the entire movie until then by backtracking into the last chapter - and promptly isn't heard of again until pretty near the final act. I do suppose it works fine, but it would have been just as easy to show it the first time and not need to spoon feed the audience that particular part - especially after already leaving all sorts of bread crumbs throughout.
Actors do a splendid job here, as one would expect. It's a good thing they do, as well, as it's pretty near the only main draw to this movie in the first place. It's a bit of an issue when your playing out a big drama like this, so I won't particularly blame the movie itself, but it really is that slowly burning line of powder leading up to a keg - and despite those tensions rising, there isn't a whole lot that actually happens as it goes on. Still, the line delivery is great, and even though parts of the world cease to feel authentic each character is at least distinguishable from the rest at a glance and listen. It feels like there was care to give each character a personality, even if you don't care in the slightest about the character and whatever length of time they spend on screen.
Costumes play well into lending each character their own feel, and the set does a good job of setting the mood as well. There were moments when the imagery and music evoked images of The Thing as I watched, and although it may not have involved aliens it still provided an ample feel of isolation to make the tension easier to build. Outside of those few particular moments, I don't recall much of the soundtrack on display here, but that isn't a terrible thing considering that most the time my focus was on the characters and the story being told.
