The narrative of "In the Penal Colony" unfolds in a barren valley on a remote island, where an explorer is invited to witness a peculiar execution method. Central to the story is an intricate machine designed for capital punishment, observed by four main characters: the officer, the explorer, the condemned man, and a soldier. The looming presence of the Commandant, who extended the invitation, suggests deeper themes of authority and tradition.

The Unveiling of the Machine

The explorer, though invited, shows little enthusiasm for the event and seems detached from the fate of the condemned man. Meanwhile, the officer busies himself with final adjustments to the execution apparatus, wearing a cumbersome uniform that reflects his nostalgia for home rather than practicality in the tropical climate. His attire speaks to his identity as a colonial officer, clinging to the vestiges of his past.

Mechanics and Origins

In an effort to enlighten the explorer, the officer dives into a detailed explanation of the machine's workings. He credits the former Commandant, the machine's inventor, with not just this deadly device but the entire organization of the penal colony. Among the apparatus's components are the intricately designed "Bed," "Designer," and "Harrow," each playing a part in the gruesome ritual. The officer's words reveal the machine's purpose: to etch the crime onto the body of the condemned, a process vividly described amidst the language barrier between the officer and his audience.

Dissatisfaction with the New Commandant

As the officer continues, his discontent with the current Commandant becomes clear. The new leader's lack of interest in the execution machine hints at a gradual shift away from the colony's past practices. The officer bemoans the absence of spare parts and laments the loss of his role as the colony's unquestioned judge, proudly asserting his credo that "Guilt is never to be doubted." The prisoner faces execution for allegedly falling asleep during his duties—a minor infraction carrying severe consequences.

The Explorer's Ethical Dilemma

With the execution imminent, the explorer grapples with a moral quandary, feeling a fleeting urge to save the condemned man. His role as an outsider and the complexities of intervening in foreign customs weigh heavily on his conscience. Despite the officer's hope that the explorer might champion the machine's continuance, the explorer's foreignness and internal conflict impede decisive action.

Confrontation with the Officer

Ultimately, the explorer voices his disapproval of the execution process, though acknowledging the officer's earnest conviction fails to sway his judgment. In a dramatic turn, the officer, left without an ally, releases the prisoner and subjects himself to the machine, adjusting it to inscribe "BE JUST" as his final message. The self-execution spirals into chaos as the machine malfunctions, leading to the officer's untimely demise.

The Aftermath

Upon observing the officer's lifeless face, the explorer finds no trace of promised redemption. He departs the valley alongside the soldier and the prisoner, navigating through a town of decayed structures to a teahouse. Here, the explorer encounters the grave of the old Commandant, discreetly positioned beneath a table, with patrons giving way to the foreigner. An inscription predicts the Commandant's return, hinting at the enduring grip of past ideologies. After giving a few coins to the gathered laborers, the explorer boards a ferry to his steamship, resolute in his decision to journey alone, leaving behind the soldier and the prisoner at the harbor steps.