23rd December 2024. Rob Tanner should have been enjoying a rare day off from his life-consuming work as Chief Operating Officer at one of the country's largest banks. But a panicked phone call from a senior colleague forces him to put his Christmas plans on ice: more than a thousand of the bank's accounts have seen their balances increased by a factor of ten. Exactly ten. Through the inexplicably simple addition of an extra zero. And when the inflated balances prove to be neither early Christmas gifts, nor a botched computer system upgrade, but the most sophisticated cyber attack in history, Tanner finds himself in the eye of a 'Black Swan' storm no one predicted, but anyone could have anticipated.