Nadene Ghouri presents On Spec. The trailer for Season Four - The Walls We Build.

In this special edition of On Spec, Host Nadene Ghouri tells the story of how her search for a surrogate mother for her child brought her to Ukraine, and how she found herself repaying the ultimate kindness by helping one woman flee the war there.

The Colorado River runs through seven US states and crosses into Mexico, helping sustain 40 million people living along it’s banks and far beyond. It’s been dammed 15 times, part of an effort to capture its waters for the people living along its banks. But the Colorado is drying up, and communities along the river will soon face cuts in their allotted shares, part of a complex treaty between Mexico and the US on how to distribute the water.

All On Spec episodes and Nadene’s Q and A’s with the reporters of each episode can be found here.

Nadene Ghouri goes undercover to expose the trade in children by some charities registered in the United States and operating as businesses in Liberia.

Nadene Ghouri investigates the illegal market in fertility drugs and examines claims that it could lead to women taking big risks with their health.

Meat from the offspring of a cloned cow has been sold and eaten in the UK. Nadene Ghouri investigates how it happened and asks whether anyone is likely to be at risk. She traces the animal's journey from Wisconsin in the US to a dairy herd in the Scottish Highlands, and finds out how the international market in animal embryos made it all possible.

Back in the 1960s, a young English hippy arrived in Kabul, looking for a good time and cheap drugs. Instead he found there a tribal culture that entranced him.

Forty years on, he's still there - now a Muslim, a trained Imam, a journalist, a Pashtu speaker and a man with a mission.

His name is John Mohammed Butt and he's made it his life's work to spread a message of peace and tolerance in the tribal regions that straddle Afghanistan and Pakistan.

But as reporter Nadene Ghouri discovers in Assignment, that message has made him a target for militants.