Shipwrecked by a storm on Slave Island, the survivors are forced, according to the law of this Republic, to exchange their status: from master, Iphicrates becomes the slave of his slave Arlequin, and Euphrosin, from mistress, becomes the slave of her slave Cléanthis. But this exchange merely replaces oppression based on custom and tradition with oppression based on resentment and revenge. Only a transformation of hearts can make inequality of rank acceptable and just by making everyone recognize the equality of souls. This transformation is the work of Arlequin, who forgives his master, returns his power to him, and whose generosity is contagious.