In Part I of The Amazing Adventures of Kavalier and Clay, Josef tries to emigrate out of Czechoslovakia but encounters a technicality problem with his emigration papers. As a result of the technicality, Josef is forced to return home to Prague.
Instead of returning to his family and telling them that there was problem with his papers, Josef seeks out his mentor Bernhard Kornblum for help. Kornblum agrees but on the condition that Josef try next time by going first into and departing from Lithuania. Kornblum keeps Josef's secret all the while that they have adventures in Prague, like finding the Golem and smuggling--and Josef--out of Czechoslovakia.