Discworld 28: Amazing Maurice, 2022 Ed.

Even wizards produce leftovers. But a wizard`s rubbish is laced with magic, and for the rats that forage this rubbish, the magic has changed them - they can speak and read, and have rather grand ambitions for a comfortable retirement. Which is perfect for a con-cat like Maurice. He has his own magical talents, and wants to get rich quick. Together with the rats, and young (rather simple) Keith, the `piper`, they work the towns to create their very own plague of rats - then lure them away for cash. But in the run-down town Bad Blintz, this little con goes wrong, and suddenly these educated rodents aren`t playing to the piper`s tune . . .