In Dragnet: The Big Present, detectives Joe Friday and Frank Smith are tasked with solving a series of peculiar burglaries that have recently struck Los Angeles markets. Over the past two months, a thief has broken into 18 stores, leaving no solid leads or clues regarding his identity. The detectives quickly realize that the burglar's method is unusual; he only steals petty cash and leaves behind empty milk bottles at each crime scene. This odd pattern suggests a deeper story, hinting that a juvenile may be involved.