Rats and mice live in the margins of the empires of dogs and cats, with homes that connect to the Underneath — a vast collection of warrens, tunnels, caves, and other hidden places. It is a dangerous place full of unexplained phenomena and terrifying creatures. But it is also full of wonders of ages past and the thrill of discovery. For the rodents believe Man was part of something called Science, a way to learn power through study, observation, and experimentation. Perhaps through the exploration of the Underneath, they can rediscover Science. It’s time to listen to the squeaks in the deep. Squeaks in the Deep is a chronicle sourcebook for both Pugmire and Monarchies of Mau. It’s usable with either game, or as part of a joint experience.