Simon Reeve travels from Alaska to Central America.

From Alaska to Canada
The expedition begins at the northernmost point in Alaska, journeying south through Canada to the border with the US. In Denali National Park, he witnesses first hand the impact of climate change on a glacier. He also hunts caribou with native Americans, hears from both sides of the conflict over a controversial oil drilling plan, and discovers Vancouver's opioid addiction crisis.

From Montana to Colorado
Simon travels down the Rocky Mountains from Montana to Colorado. In the wide-open prairies of Montana, the cowboy way of life is under threat from a long-term decline in the rural economy, but Simon meets a former Silicon Valley executive who has envisaged a new future for the land. In a country with the highest incarceration rate in the world, Simon's final destination on this leg is a Colorado town that depends almost entirely on 11 prisons. Simon witnesses how inmates are put to work for the state, and how virtual reality is being used to prepare prisoners for life on the outside.

California
Simon travels the length of California. He climbs to the top of one of the world's tallest trees, and meets the fire crews tasked with tackling the ever-present danger of wildfires, a growing threat given the state's changing climate and chronic shortage of water. He also meets street doctors providing much-needed medical support to people living in extreme poverty and visits a city on the desert for Americans who have dropped out of the rat race entirely.

From Texas to southern Mexico
Simon travels from Texas to southern Mexico, meeting a woman who risks her life to take supplies to migrants stranded on the Mexican side of the border in Reynosa, one of the country's most violent cities, which is dominated by a powerful criminal organisation. He also ventures into the rainforest to explore the Maya city of Yaxchilan, and meets the modern-day descendants of this civilisation, who are increasingly marginalised and treated as second-class citizens.

Central America
Simon travels across Central America, from the Caribbean to the Pacific. Along the way, he goes diving on a coral reef on the coast of Belize, and witnesses a gun battle between park rangers and intruders in Chiquibul National Park. He also discovers how climate change has left Guatemala devastated by famine and drought, reports on measures to curb gang violence in El Salvador, and learns how Costa Rica aims to become the world's first carbon neutral country by 2021