Upstream Color is an undulating  new tangle of a film by writer/director/actor/composer/editor/sound editor Shane Carruth, who earned a lot of well-deserved good will with his previous effort, the inside-out time travel story Primer.

In terms of scope and subject matter, Upstream Color can function as a kind of secular answer to writer/director Terrence Malick’s deeply religious The Tree of Life.  Where Malick pulled the camera way back in time and space to make his point that the human condition is only a microscopic manifestation of infinitely larger, more numinous phenomena, Carruth’s intricate new film instead zooms in on infinitesimal biological processes, suggesting that they hold sway over human action in multiple compelling ways.

Of course we are fortunate enough to live in a Universe that doesn’t have to fit neatly into one of these worldviews or the other.  Like Tree of Life, Upstream anchors its heavier material in naturalism:  the  love story between Carruth and Amy Seimetz, two bruised victims of an un-masterminded biological conspiracy.  It isn’t as easy to like as Primer, but this much more linear and emotional film scores points for not being afraid of its own weirdness.