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.

In Italy in the 1930s, sky pirates in biplanes terrorize wealthy cruise ships as they sail the Adriatic Sea. The only pilot brave enough to stop the scourge is the mysterious Porco Rosso, a former World War I flying ace who was somehow turned into a pig during the war. As he prepares to battle the pirate crew's American ace, Porco Ross...

Following a bomb scare in the 1960s that locked the Webers into their bomb shelter for 35 years, Adam now ventures forth into Los Angeles to obtain food and supplies for his family, and a non-mutant wife for himself.