Guy Martin continues his 10,000-mile adventure around Russia to find out how the biggest country in the world really works. His journey in this episode starts in Archangelsk, a remote city in the frozen north that is home to Europe's only diamond mine. Guy works at every stage of this billion-dollar process, from driving one of the world's biggest dumper trucks to witnessing a laser saw cut a 200-carat diamond worth millions of pounds. He then realises a lifetime ambition to visit Kamaz, Russia's biggest automotive manufacturer, and drive one of their famous Dakar Rally-winning trucks, before visiting the Kalashnikov factory to see how the AK47 - the most popular gun in the world - is made.