Shane Carruth is some kind of genius. Either that or his films deal with such complex, elaborate narratives that it just seems like he is a genius. But he has developed a cult following; his last movie, Primer, has websites dedicated to figuring out the various timelines. [Here's an amazing timeline jpg].
He takes his stories one step further into a morass of [il]logic than such films as Memento or Inception by Christopher Nolan. Which is perhaps one reason he is not yet well know and perhaps one reason he is self distributing his latest film.
I'm not going to spend time recounting the plot. If you want all the bits and pieces described succinctly and well go here. [Although preferably after you watch it].
I think it's best to go into the movie cold, knowing as little as possible. Suffice it to say it is a romantic thriller, science fiction film that deals with such unrelated things as maggots, natural narcotics, memory loss, pigs, mind control and Thoreau's Walden. Not necessarily in that order.
One aspect I particularly like about Upstream Color is that it keeps its engrossing, enigmatic narrative to the end without letting the audience down with a disappointing, banal [is-that-all-there-is] ending. Too many films have a fantastic start but then peter out by the end with the usual Hollywood let down.
Part of the reason is that the film develops its own internal logic that defies what we would call normal everyday logic and therefore keeps you guessing long after the credits.
For a really terrific interview and FAQ with Shane Caruth go here.
Go see it.