The Mekong is South East Asia's greatest river, the 'Mother of Water' that brings life to millions of people from the paddy fields of Vietnam to the mountains of the Tibetan Plateau. In this ambitious, entertaining and illuminating series, Sue Perkins goes on an extraordinary journey, spanning nearly three thousand miles, to explore lives and landscapes on the point of enormous change. Across four episodes, she travels upstream through Vietnam, Cambodia, Laos and China, towards the Mekong's source high in the Himalayan glacier. In this third episode, Sue reaches Laos, one of the poorest and least developed of all the Mekong nations. It's a country shaped by both Buddhism and Communism, and has hardly changed for centuries. Today, the beauty of its landscapes and people is bringing in foreign tourists - backpackers in search of un-spoilt Asia. Sue spends time with Bounsom, a fisherman who's turned to tourism, setting up a restaurant on the beach. And she visits Luang Prabang, a beautiful town which was once the Royal City of Laos and is now a Unesco World Heritage site, famed as the centre of Buddhism. Thought to be the home of more monks than anywhere else in Asia, Sue spends a day with the novice monks, and gives a surprising English lesson in the temple's school. Laos is on the verge of huge and irreversible change - massive dams are being built to harness the power of the river. After months of access negotiation, Sue films at the Xayaburi hydroelectric dam, SE Asia's biggest and most controversial engineering project. It's the first dam to be built across the Lower Mekong and will completely block the flow of the river, changing water levels, blocking fish migration and destroying fish stocks. Under strict supervision, Sue is told about the merits of the dam by the Vice Minister for Energy and Mines, Mr Viraphonh Varavong. When the waters rise, thousands of people will be forced to leave their traditional homes, so she is given a tour of their new village, complete with electricity. Having seen the effects of damming in Vietnam and Cambodia, Sue grapples with the complexities of projects such as this. While the Xayaburi Dam will bring economic benefits to Laos and beyond, the industrialization of the Mekong will harm the livelihoods of tens of millions of people downstream. Foreign investment is coming to Laos on projects beyond the dams. The government has tempted Chinese developers with tax incentives to create tourist playgrounds in an area branded as the Golden Triangle Special Economic Zone. At the river's bank, Sue is met by a stretch limo to take her to a Las Vegas-style casino, built for Chinese VIPs who aren't allowed to gamble in their own country. It's a world away from the charm and serenity of the Laos she's fallen in love with.