On March 26, 1869, a group of Entrerrians recruited by Urquiza and sent to reinforce the regiments of the line west of the province of Buenos Aires, tried to escape and were shot in Loncogüé by order of President Sarmiento, without prior trial and without sentencing. Thanks to the jealousy and interests facing Bartolomé Mitre with the president, the incident became public knowledge. The Argentine Nation described it as an act atrocious, unheard of, unique in the history of military law. Through a careful investigation, Sergio Carciofi shows the interests that linked Urquiza, Sarmiento and Miter himself and reveals the interweaving of one of the ignored crimes against humanity that marked Argentinian history.