‘I won’t always give satisfying answers,” filmmaker Shane Carruth said, by way of warning, in an interview in early January. The premiere of his long-awaited second feature, “Upstream Color,” at the Sundance Film Festival was weeks away at the time. He was finishing the sound mix and working out the details of a self-distribution plan.

But the greatest source of anxiety was the prospect of having to talk about his movie. “I hate even the idea of a synopsis,” Carruth said. “When stories are really working, when you’re providing subtextual exploration and things that are deeply layered, you’re obligated to not say things out loud.”

Subtexts and layers abound in his new film, which combines elements of an abduction plot, a love story and a cosmic science experiment. “Upstream Color” trended heavily on Twitter when Sundance announced its lineup, and the anticipation has much to do with the cult status of Carruth’s first feature, “Primer,” the Dramatic Grand Jury Prize winner at that festival in 2004.

Carruth, 40, a former engineer and self-taught filmmaker, made “Primer,” a deadpan time-travel fantasy, for a reported $7,000, taking on the roles of director, writer, producer, actor, cinematographer, editor and composer. A feat of DIY enterprise and polymathic ingenuity, the film lent itself to repeat viewings and endless theorizing about its laws of physics and metaphysics, which ensured a robust afterlife in home video and on message boards.

Carruth said that the response to “Upstream Color” has been overwhelmingly positive. But what irks him is the suggestion that the film, like “Primer,” is a puzzle movie in need of solving.

“It’s funny that some of the early reviews used words like opaque and obscure,” he said. “And then they list the plot, beat by beat, and pretty much nail it. You’re sort of like, well, what was so opaque then?”

The most provocative aspect of “Upstream Color” is the way it unfolds, as a skein of associations and in a barrage of fragmentary images and clipped conversations. Increasingly prone to slippage and ellipsis, the film builds to a wordless finale in which, as Carruth put it, “everything deteriorates into the ether.”

“I believe that it’s trying something new in terms of film language,” said Carruth.

“Upstream Color” is a movie about the limits of knowledge that doubles as an experiment in inference. “It’s about people building their own narratives when they don’t have anything to hold on to,” Carruth said. “They’re accumulating their identities out of whatever they find around them.”

An open-ended fable, the film has a pronounced metaphorical aspect. “You could do the same story about any number of things where people are being affected by outside factors that they can’t quite speak to,” Carruth said. “The end result is the same, whether you’re talking about religious or cosmic or political beliefs, or being affected by a chemical or by a relationship.”