Traditionally, this relief has been identified with Totila's conversion, a Gothic king whose figure was usurped by an impostor that was quickly discovered by the saint founder. In fact, it represents the conversion of the Gothic Zalla, a cruel character of Arianist religion, that wanted to rob a farmer that gave his properties to Saint Benedict for him to guard; the farmer was brought to Saint Benedict in his monastery in Montecassino, shackled and dragged by Zalla's horses, who demanded the money; the saint miraculously untied the farmer and the cruel Goth, "terrified by the strength of such power, fell from his horse" to prostrate himself before Saint Benedict. The relief, one of the best achieved of the altarpiece, shows to following moments of the story: up to the left, the arrival of the farmer to the monastery dragged by Zalla's horses, and in the center, the moment in which Saint Benedict punishes the wicked, presented as a character with a cruel and scruffy face, making him fall from the horse, that squirms stroked by the power radiating from the saint. The great dynamism of the central scene of the relief, where everything is unrest and violence, contrasts with the rotundity and stillness of Saint Benedict that seems to be out the time and space. His figure stands out in the foreground, almost standing-alone and adjusts the depth of the other elements of the scene, that flatten reaching just an insinuation of the background buildings. Again, diagonal lines structure the composition, converging in the farmer's body and highlighting his role. The polychromy is one of the most beautiful ones of the altarpiece, with fine works in estofado style on the character’s clothing and the architecture