Humbert is a hardworking horse who happily pulls a cart for Mr. Firkin, a friendly scrap iron dealer. Humbert loves his daily job, but deep down, he feels a little jealous. He looks at the fancy horses with their shiny coats who get the honor of pulling the Lord Mayor of London's beautiful coach and wishes he could do something that important. Everything changes on the day of the huge city procession. While the crowds are cheering and the parade is moving through the streets, a sudden disaster strikes. The Lord Mayor's magnificent coach completely breaks down, and the entire celebration comes to a halt. It turns out the only horse close enough to save the special day is humble Humbert and his trusty cart. See how an ordinary scrap cart horse becomes the absolute star of the biggest parade in the entire city.