Francoise Paulette is a legendary aboriginal Elder living downstream of the tar sands, the veteran of many battles to defend his lands from industrial encroachment. His first victory was a Canadian Supreme Court decision in 1973 – the Paulette Caveat – which sparked the era of Native land claims. Now, the documentary follows his campaign to halt the expansion of the tar sands, a journey that takes him from his bush home in northern Canada to Copenhagen, Oslo and New York.

James Cameron, Director of the environmental blockbuster Avatar, became an unexpected ally of the downstream people and a character in the documentary. From Elder Francois Paulette’s first visit to Cameron in New York to Cameron’s three-day visit to the tar sands in 2010, our cameras had exclusive access to his conversion. Cameron and his Avatar filmmaking team describe how the fictional mining station on planet Pandora was inspired by Canada’s tar sands.

Dr. John O'Connor, a soft-speaking community doctor from the downstream community of Fort Chipewyan, began to notice a rare form of cancer turning up in extraordinary numbers. He called for medical research and went to the media, but the Canadian Government accused him of “raising undue alarm”. Driven from his practice, and now vindicated of wrongdoing as the true state of toxic pollution emerges, the documentary follows his return to Fort Chipewyan.

Dr. Erin Kelly, an expert on water contamination, worked in secret to carry out a controversial study of oil pollution in the Athabasca River flowing through the Canadian tar sands. What she found was shocking – the equivalent of a major oil spill occurring annually in a river at the heart of an aboriginal hunting and fishing culture stretching to the Arctic Ocean. The documentary is alongside her and her colleagues as they carry out their research and then bring the tragic results to the downstream community of Fort Chipewyan.

David Schindler, winner of the Stockholm Water Prize and one of Canada's most decorated scientists, led an historic research project, the first ever to examine pollution from the Canadian tar sands. In 2009 and 2010, he published his team's results in the prestigious Proceedings of the National Academy of Science. The documentary follows Schindler and his researchers as they carry out their research and documents the aftermath as the results make world headlines.