A London cabbie tests his skills on some of the most chaotic streets in the world in Mumbai India. His host is Pradeep Sharma, who lives with his extended family in a tiny two bedroom house and earns less than ten pounds a day for his long and stressful shift. As Mason takes his life in his hands to learn the Knowledge Mumbai style, he also begins to understand the plight of the millions of migrant workers who flood into India's cities looking for work. They often encounter poverty, discrimination and hostility. Inspired by their sheer determination, Mason's final challenge is to go solo in an Indian taxi, picking up passengers, finding his way around and earning his crust in the madness of the Mumbai rush hour. It's like 'Mad Max meets the Kumars' as Mason puts it.

Dairy farmer Richard Gibson is swapping the damp surroundings of Devon to live and work with Samburu tribesmen, who herd their cattle in the parched and desolate mountains of northern Kenya. British farmers have suffered from low milk prices and squeezed margins but it is nothing compared to the struggles of Richard's host, village elder Lemerigichen. In recent years drought has decimated the herds in this region, forcing many Samburu off their land and into the poverty of local towns. Richard launches himself into an alien lifestyle - sleeping rough in the wilderness, drinking cow's blood and digging and digging to find water. The two men form a touching bond through the love of their animals and the basic drive to support their families, whilst Richard gains an insight into what it is like to tend a herd when surrounded by lions, leopards and hyenas.

Firefighter Neil Fairhall is leaving his fire station in Hayward's Heath and heading to the Amazon to fight some of the biggest forest fires in the world. While a lot of a British firefighters' time is spent attending small fires and false alarms, during the dry season in Mato Grosso state, the Jatoba Fire Brigade, part of Alianca da Terra, can work for four days at a time trying to save the forest from fire. As Neil trains and works with fire chief Edimar Dos Santos Abreu and his crew, he learns that the blazes are often started deliberately in order to clear the forest for illegal agriculture and that this now represents the single biggest threat to the Amazon. It is tough and brutal work as a team of just five men work across an area the size of England in a seemingly hopeless battle.

London bus driver Josh returns to the chaotic streets of Manila in the Phillipines.

Andy Giles returns to the fishing community in Sierra Leone whose survival was threatened.

Wilbur Ramirez revisits Jakarta to see if he can improve the lives of the city's binmen.