Multiple-time New York Times–bestselling sewer-surfing super-sleuths Mango and Brash are back in the ninth volume of the mega-smash-hit InvestiGators series! The InvestiGators’ latest case is a dairy disaster! The city's water supply has been replaced with milk and the newest feline agents, the InvestiGatos, don’t seem to be complaining. What’s with the simian scientists and why is the rain green?! All will be revealed in this sticky volume of InvestiGators!