The narrative begins when Manuel Perez, a recently paroled Mexican man with a wooden leg, arrives early at the Monte Vista sheriff's office asking for help and claiming to be entirely destitute. Sheriff Joe Cook and his deputy, Shorty McKay, sympathize with the former rustler and prepare to help him find work on a nearby sheep ranch. However, their plans are immediately derailed when old Grandpa McMeel bursts into the office to report suspicious nocturnal activity beneath the Third Street bridge. McMeel and a local young man named Fred Speers describe seeing two large figures digging up a heavy, long box in the middle of the night and dragging it across Coyote Creek without leaving clear footprints.
The town quickly becomes consumed by wild rumors regarding the mysterious excavation. Many citizens suspect that the hole held an exhumed body, while others whisper about smuggled border jewels or forgotten bandit loot. Sheriff Cook worries deeply about the case because county commissioners are facing spring elections and threaten to penalize the local law enforcement for incompetence if the mystery goes unsolved. Under mounting political pressure, the sheriff searches the bridge banks again and stumbles upon an old, empty wallet containing a yellowed newspaper clipping from eight years prior. The clipping details an unsolved Alamosa bank robbery involving eight thousand dollars in cash and negotiable securities.
Convinced that the stolen bank loot had been buried under the bridge all those years and only recently retrieved, the depressed sheriff prepares to write his letter of resignation. Before he can submit it, Deputy Shorty McKay arrives alongside Perez and Fred Speers with a bundle of currency recovered from the suspects. Shorty explains that the box never contained bank loot at all, but rather Perez's accumulated rustling earnings buried before his imprisonment. Perez and Speers had orchestrated an elaborate deception, inventing a vague description of the thieves and planting the old newspaper clipping to permanently mislead the authorities.
Shorty reveals how he saw through the facade by checking prison release logs, tracing recent fingerprints on dusty newspaper office files, and confronting the suspects at the ranch. With the stolen cash recovered and the clever plot exposed, the county commissioners are overjoyed and immediately promise their full political support for the upcoming election. The sheriff decides against resigning and gratefully resolves to reappoint Shorty as his deputy for another term.
