Scotland is plagued with over 50,000 drug addicts and one of the roots of this addiction is the opium poppy. In this second episode, actor Brian Cox travels to China to discover how the seeds of this modern-day addiction were planted during the height of Britain's trading empire. Since then opium has fuelled the world's largest drug-smuggling operation, earned vast fortunes, triggered war with China and inspired medical breakthroughs. Brian Cox reveals how Britain unleashed the most dangerous of addictions on the world, and how the consequences still haunt us today.