In the midst of World War I, an ambitious French general orders a suicidal attack on a well-fortified German position known as the Anthill. Colonel Dax, a French infantry commander, is tasked with carrying out the impossible assault. Despite his objections, Dax leads his men in the futile charge, which unsurprisingly ends in disaster, with heavy casualties and an inevitable retreat under the withering enemy fire. The attack's failure incites fury among the high command, who seek to deflect blame and preserve the army's morale.

In the aftermath, the general demands a trial for cowardice against the soldiers who retreated. Three men are arbitrarily chosen to stand as scapegoats for the failed offensive, each representing a different company from Dax's regiment. Colonel Dax, a former lawyer, steps forth to defend the accused men in the court-martial, desperately trying to save them from the firing squad. The trial, however, appears to be a sham, with the verdict seemingly predetermined by the callous and prideful military leadership, which remains indifferent to the soldiers' fates and determined to establish a harsh example to maintain discipline within the ranks.