The film retraces the events of a trail in the Pyrenees, which fleeing fascism that was infecting the heart of Europe. Catalans and internationalist militants fleeing the Franco regime before; Jews, communists and dissidents by the Nazis shortly after.
Set in the world of bugs where spiders are the cops, a detective boards a seaplane to San Francisco after finally capturing his arch nemesis, but a murder on his flight draws him into a plot that threatens both the human and bug worlds.