Terry Pratchett was diagnosed with a rare form of early onset Alzheimer’s in 2007. Fortunately, it’s not evident in this Discworld book.
Moist von Lipwig, con man extraordinaire, finds himself in charge of the Royal Bank of Ankh-Morpork and the Royal Mint. The people don’t trust the banks much. In an effort to get money flowing, he introduces paper money to Ankh-Morpork. Lipwig, like his creator, is an acute observer of people, and pulls it off against the odds.
Pratchett does his usual trick of holding a fun-house mirror up to some aspect of human society. This time, it’s money and economics.