The love between Amadis and Oriana is tested, and treachery tears apart the court of King Lisuarte.
[Yedra Castle in Cazorla, near Jaen, Spain. Its original construction dates back to the 12th century.
Not far across the sea from Great Britain lies Firm Island, so named because a narrow strip of land connects it to terra firma. Long ago Apolidon, before he became Emperor of Constantinople, lived there and left behind enchantments to test loyalty in love, beauty in women, and skill in arms. The knight who passes the test of skill in arms would become lord of the island.
Amadis, Galaor, Florestan, and Agrajes leave Queen Briolanja and decide to test themselves at Firm Island. Amadis wins and becomes its lord, to the joy of all. But Oriana wrongly believes he loves Briolanja instead of her, so she sends him a letter withdrawing her love and ordering him never to come before her again. When Amadis receives the letter, he loses the will to live and leaves the island as secretly as possible to wander desolate in the mountains.
There he encounters a foolish knight singing of his love for Oriana. Amadis easily defeats him. The knight is Patin, from Rome, and will eventually be its Emperor.
Everyone begins to search for Amadis, who is dying of grief, but he has found a hermit who takes him to spend what little remains of his life at his hermitage on an island named Poor Rock. The hermit renames him Beltenebros, which means "Handsome Gloom."
Oriana learns that her letter made Amadis want to die. Ridden with guilt, she sends the Damsel of Denmark to Scotland to look for him. Her ship is blown off course to Poor Rock, and she finds him, wasted away by grief, and eventually recognizes him by a scar on his face. She gives him a letter from Oriana confessing her guilt. He immediately leaves with the Damsel.
Meanwhile, in London, King Lisuarte has been challenged to a battle by King Cildadan of Ireland, who has several giants and the sorcerer Arcalaus on his side. Lisuarte begins to recruit one hundred knights to fight with him, including Galaor, Florestan, and Agrajes.
Oriana has gone to rest at her castle, Miraflores, near London, and sends word to Beltenebros to come there. On his way he defeats some of King Cildadan’s allies, and his esteem as Beltenebros grows in London. He arrives at Miraflores at night and is welcomed into Oriana's arms. He spends the next week there with her, both overjoyed with pleasure.
Back in London, an elderly squire arrives with a magic sword and wreath of flowers to test the loyalty of lovers. Beltenebros and Oriana go there, disguised, and win the test, so they need never doubt each other’s love again.
Beltenebros joins the hundred knights fighting for King Lisuarte against King Cildadan. The battle is long and cruel, but in the end, Beltenebros rescues Lisuarte and shouts, “Gaul, Gaul, for I am Amadis!” This rallies Lisuarte’s men and they win, led by Amadis.
But Galaor has been almost fatally injured. Twelve damsels arrive to take Galaor and the injured King Cildadan away in a ship. When the men awake, they discover the damsels were sent by Urganda the Unrecognized, a sorceress,who nurses them back to health.
King Arban of North Wales and Angriote de Estravaus are being held and tortured by the widow of one of King Lisuarte’s opponents. She offers to send the valiant knight Ardan Canileo to fight Amadis, and if he wins, she will free them. Amadis accepts. But his magic sword is stolen and delivered to Canileo.
The battle begins, and it is fierce. Oriana watches from a window, and her presence gives Amadis great courage. He makes a bold move to disarm Ardan, kills him, wins the fight, and recovers his sword.
Although King Lisuarte has enjoyed great good fortune for many years, he has two scheming old counselors in his court, and they are jealous of Amadis. They tell the King that Amadis is planning to take the kingdom from him. Foolishly, the King believes them and tells Amadis and his friends to leave.
That night, Amadis secretly meets with Oriana, and in bed, explains that he must go. She is heartbroken but grants permission. The next morning, Amadis calls together many knights and tells them he is departing for Firm Island, explains why, and invites them to accompany him. Five hundred leave with him.
Eventually King Lisuarte discovers the treachery, but it is too late.
And Oriana discovers she is pregnant.