London high-society mouse, Roddy is flushed down the toilet by Sid, a common sewer rat. Hang on for a madcap adventure deep in the sewer bowels of Ratropolis, where Roddy meets the resourceful Rita, the rodent-hating Toad and his faithful thugs, Spike and Whitey.

As a wild stallion travels across the frontiers of the Old West, he befriends a young human and finds true love with a mare.