Moist von Lipwig has been running the Post office, and has turned it round such that it is running smoothly - and as a result he's bored. He shortly after this becomes un-bored when he inherits a dog called Mr Fusspot, who, it just so happens, has been bequeathed 51% of the Bank and it's associated mint. Moist has an interesting time changing the manner of banking for the majority of the people from a sock under the matress to an actual bank. This meets with opposition from several sources - there's the Lavish family, who have owned the bank, and now own less than half of it - there's Mr Bent, the chief Clerk, who has a dark secret and doesn't "do" humour, or fun or words, or any of the things that Moist excels at - and there's the issues with the gold standard and weaning people off gold coins and onto notes. Unfortunately the person he wants to design his money is currently in jail, about to be hanged, after Moist testified against him for forging stamps. It all gets very complicated, not helped by the arrival of a fair number of Golems and Adora Belle Dearheart.