Four and a half thousand miles away from here lies a slice of British paradise – a sun-soaked Caribbean island the size of Bognor Regis: the Cayman Islands. Watched over by a Governor appointed from Whitehall, the Caymans are well and truly British, but with one big difference: no-one seems to be paying a penny of corporate or income tax.

Not locals. Not expats. Not big global corporations. And thanks to this tax-free status, Cayman has built a finance industry that’s brought one and a half trillion pounds into its banks. There are twice as many companies registered here as there are people. But what’s really going on? Is it tax avoidance on an epic scale? President Obama thought so – he described one building here, Ugland House, home to nearly 20,000 registered companies, as “either the biggest building, or the biggest tax scam, on record”. And are our household brand names mixed up in it?

Now Jacques Peretti has been given unprecedented access to Cayman’s politicians and financiers, its millionaires and the ordinary British expats who’ve built a life here in the sun. He’s on a mission to get to the heart of what makes Cayman tick – and to uncover the unexpected truth about what its existence really means for all of us.