Landmaus und Stadtmaus auf Reisen

Emily and Alexander visit their cousin Ernestine in San Francisco. They enthusiastically ride a cable car through the city. They witness a bank robbery. The thief is the cable car driver Murphy, but he has the mask of Mister Hallidie on to take revenge on him. Of course, Hallidie is arrested and taken away. His daughter Jeannie is a friend of the mouse Ernestine, so Alexander and Emily take up scent with their sleuths, solve the case and convict the real culprit. It is exactly the time when the big quake takes place in San Francisco. They can't prevent it, but at least they can warn about it.