One of the great past Sundance success stories was "Primer," a mind-bending science-fiction time travel thriller made on a shoestring budget of $7,000 by former engineer Shane Carruth. The film took the top prize at Sundance in 2004 and was nominated for four Independent Spirit Awards the next year after its theatrical release.
Despite many rave reviews and a steadily growing cult audience, Carruth's long-awaited follow-up feature "Upstream Color" has finally materialized and will debut at the 2013 Sundance Film Festival in January.
So how does a filmmaker follow a film whose twisty plot necessitates a full-color diagram to explain it on its Wikipedia page? With an even stranger film.