Shane Carruth's debut, Primer, is now well known for being an elusive, confusing, intricate little piece about a couple of guys who build a time machine, and test out its powers within reasonable limits. Carruth has followed this film up with Upstream Color, a film so inexplicably complicated that explaining the plot would be both redundant and ridiculously long. Mind control maggots, pigs or fate, love conquers all, white flowers turning blue is a conspiracy. If any of that makes sense, congratulations, you're Shane Carruth and you've just made your second feature.

To say Carruth's film is aggravating is an understatement, perhaps as a time travel nerd Primer was an easier venture to understand, but Upstream Color seems to go about actively confusing the audience on every level at every time. Just when someone might go "ahh, I get it" in the cinema, the film cuts to something else and everything you thought you know was wrong, and what you now think is even more wrong. The film begins incredibly well, after a short stint watching maggots get cola sieved on them, and kids doing some incredible fighting, we see a woman manipulated in some really incredible and horrible ways due to this new pill, and the squirm-inducing results of all this maggot efforts. But from there-on, the aftermath of the manipulation and the incredibly poorly handled pigs element of the film, it all becomes a puzzle wrapped in an enigma that isn't worth solving because at the core we just don't care about the two protagonists, Kriss and Jeff (Amy Seimetz and Carruth).

Whilst it's lovingly shot, and at times really intense, Upstream Color really seems to have contempt for every audience, actively sticking a middle finger up at them, not offering information is fine when there's something worth figuring out, but the mysteries within Upstream Color are so lifeless and beyond logical reasoning that it's just a mixed bag, or sack, floating down a river, slowly drowning. Good performances and cinematography, and a gripping first half hour, really add to the experience, but the last hour decides to screw over everyone who cares to be an active audience member that it becomes questionable why one should even care about the confusion at the heart of the picture. It's no Primer, that's for sure.