Imagine you had a few million ill-gotten pounds, rubles or dollars. Where would you stash it? You'd need to make sure no one knew it was yours, or where you'd nabbed it from. It turns out that the best place in the world for these money-stashing services is the UK. Oligarchs from all over the world use British financial services, overseas territories and even tube stations to hide their wealth. Ash meets Oliver Bullough, author of Butler to the World: The book the oligarchs don’t want you to read – how Britain became the servant of tycoons, tax dodgers, kleptocrats and criminals.