It is January 1721. London is reeling from the effects of the greatest financial scandal of the age, the collapse of the South Sea Bubble. William Spandrel, a penniless mapmaker, is offered a discharge of his debts by his principal creditor, Sir Theodore Janssen, a director of the South Sea Company, on one condition: he must secretly convey an important package to a friend of Janssen’s, Ysbrand de Vries, in Amsterdam.The package safely delivered, Spandrel barely survives an attempt on his life, only to be blamed for the murder of de Vries himself. When de Vries’s secretary, his English wife and the package itself go missing shortly afterwards, Spandrel realizes that he has become a pawn in several people’s games. British Government agents, and others, are on his trail, believing that the mysterious package contains secrets that could spark a revolution in England.

Spandrel's only chance of survival is to recover the package and place its contents in the right hands. But whose are the right hands? And what exactly are the contents?

Economic crises seem to have come thick and fast in recent decades. It’s hard to recall the particulars of the dot.com bubble that burst around the turn of the millennium, thanks to the much bigger banking bubble that’s inflated and burst since. The fundamentals of these phenomena don’t change much, though. They’re all about greed and stupidity (often the same thing) and the recurrent ability of humankind to forget that what’s too good to be true generally isn’t.

The great-granddaddy of such affairs is the infamous South Sea Bubble of 1720-21. Reading John Carswell’s masterly study of the event (The South Sea Bubble, first published 1960) when it was reissued back in the early nineties, I knew one day I’d have to set a novel in the period and the dot.com fiasco later that decade gave me all the encouragement I needed to go about it. You just couldn’t make up the mounting absurdities and crowning catastrophe of the financial madness that swept the land in 1720, but the idea for my novel was born when I discovered that the South Sea Company’s green-covered account book – the celebrated Green Book (supposedly detailing every one of the numerous large bribes paid by the company to peers, MPs and members of the royal family, including the King) went missing, along with the chief cashier, Robert Knight, on the eve of his scheduled appearance before the committee of inquiry into the scandal in January 1721. (Or was it 1720? See below!) Unlike Mr Knight, the book was never seen again. A missing repository of dangerous secrets -  irresistible stuff!

One difficulty I faced early on in the planning of Sea Change was the fact many historians and historical novelists try to gloss over – that prior to 1752 the British calendar lagged up to eleven days behind the one used in most of the rest of Europe and, more inconveniently still, the year began here on 25th March rather than, as on the continent, 1st January. In a story ranging across several countries and a total of eighteen months, I felt this truth had to be faced up to and this book is consequently one of the very few in which the events of nearly three hundred years ago are accurately dated. Businessmen of the period coped happily with the problem, by employing double dating in their correspondence. And they did so while juggling with the complexities of international trade without the benefit of the telegraph or the telephone, let alone the computer. You can’t help admiring them, even if many of them were bigger rogues than any of the fraudsters recent enormities have flushed out of the commercial woodwork.

Sea Change is my tribute to our society’s limitless capacity for deception (and perhaps above all self-deception) in financial affairs. ‘Lessons have been learned and this will never happen again’ is the standard response of our leaders. They said it in 1721 just as they say it now. And just as they will say it in the future. Because it always does happen again.