In the 1890s, a performing circus dog escapes its abusive master and is found by railway station porter Bob (Creed-Miles), who names the terrier Jim. Jim becomes a favorite of the kiddies at the local orphanage, especially young Henry (Sangster). Jim and Bob soon find themselves in a battle to save the orphanage from closure, even as the pooch helps Bob with romancing schoolteacher Harriet (Fraser) and thwarts a plot to kill Queen Victoria.