The duke, the prince of Taranto and the seneschal of Lombardy accompanied by their men, reach the abbey. Florantine having recognized the duke even before he entered her room is pretending to be sick and acts as though she is happy to see Garnier. To trick him even more, she renounces Lion. Florantine uses her sickness as an excuse to postpone their departure so that Lion would have time to come save her. Marie sends a messenger to Lion, who is near the abbey, in order to have him come save his mistress.
When he enters the room, the duke understands the betrayal and that the only solution left to him is to sell his life dearly. Lion, now defeated, is taken prisoner, together with Florantine. He remembers the prediction of the White Knight, so he sincerely repents his sins, and God sends the White Knight to help him. As soon as he is rescued, Lion pursues the duke and the seneschal of Lombardy and kills them both. Lion explains his attitude regarding Clarisse to Florantine and swears his loyalty.
He then conquers back Monlusant, where King Henry and the duke of Vauvenisse lead a procession in their honor. Lion tells them of everything that had happened since his departure from Monterose. The next morning, King Henry gives his daughter in marriage to Lion, and in the evening they have a great celebration. Bauduyn de Monclin arrives as a guest of honor during the celebration. That night, Lion and Florantine consummate their love, and he fathers twins named Herpin and Guillaume. He entrusts Florantine and the protection of Monlusant to Bauduyn.
With King Henry, the duke of Raymon de Vauvenisse and leading a great army, he enters the country of Calabria. However, before having laid siege to Reggio, the duke of Garnier reaches Rome where he wants to obtain the sanction of the pope, thanks to the influence of his cousin Gaudiffer de Savoie. The pope sends a cardinal to the battlefield with the instruction to bring back Lion and King Henry. Our hero is granted an audience with the pope during which he gives his version of events, while Gaudiffer defends the cause of the duke of Calabria.
Lion can refuse neither this offer, nor the kiss of peace from Garnier, who, in turn, is only thinking of revenge. While Garnier returns to his land and readies himself to betray Lion, the latter obtains a second audience with the pope. The pope cannot help but notice the striking resemblance between Lion and his father Herpin. The pope summons the only witness of the incident, Gaudiffer de Savoie, and he orders him to take Lion to the grave of Herpin.
