Amadis will obey his lady Oriana in all things, which may cause his undoing.
Beginning of Book II
Apolidon is a wise and mighty young knight whose parents are the King of Greece and a sister of the Emperor of Constantinople. He defeats a giant and takes over Firm Island, where he lives in great pleasure with his beloved, the sister of the Emperor of Rome. But after many years, he is called to rule Constantinople.
Before he goes, he sets an enchantment so that no one shall rule the island if they do not equal his fortitude at arms, his beloved's great beauty, and both their loyalty in love. He creates a arch at the entry to a garden that no one can pass through if they have erred from their first love.
Then he erects magic barriers of invisible warriors ready to attack at the entrance to the chamber where they had lived; no knight can pass them unless he surpasses Apolidon's skill at arms. But if the knight reaches the chamber, he will become lord of the island.
Amadis, Galaor, Florestan, and Agrajes leave Queen Briolanja in the Kingdom of Sobradisa to rejoin King Lisuarte's court, but as they travel, they meet a maiden from Firm Island and decide to go there to test its enchantments.
Agrajes and Amadis pass through the arch of the loyal lovers; Florestan and Galaor do not even try. Instead, they attempt to enter the chamber and fail. Amadis tries and succeeds and becomes lord of the island, to the joy of all.
But as ye will recall, Oriana has been given bad information and believes that Amadis loves Queen Briolanja instead of her, so she sends him a letter withdrawing her love and ordering him never to come before her again. She orders a page named Durin, brother of the Damsel of Denmark, to deliver it.
Durin reaches Amadis just after he has won Firm Island, but Amadis's squire, Gandalin, makes him wait to deliver the letter until after the celebration has ended, knowing that Amadis will overreact to whatever it says. Indeed, to Durin's distress, when Amadis finally reads the letter, he weeps and faints repeatedly with grief.
Amadis has lost the will to live. He leaves the island as secretly as possible to wander desolate in the mountains.
Gandalin and Durin follow Amadis and listen as he mourns his cruel fate in long speeches addressed to fate, Oriana, his father, and many other people whom he loves and esteems.
Meanwhile, a knight passes nearby singing of his love for Oriana. Gandalin goes to Amadis and urges him to attack this knight, and Amadis easily defeats him, then says goodbye to Durin and leaves with Gandalin.
A flashback reveals that the singing knight is named Patin and had come to King Lisuarte's court to woo Oriana. The King did not wish to give her to him, so he responded with an ambiguous answer to avoid offending him. Patin, though, he was sure he had won her and rode off joyfully.
Durin speaks briefly with Patin after his defeat by Amadis, then leaves to tell Oriana how Amadis has reacted to her letter.
Galaor, Florestan, and Agrajes learn that Amadis has left Firm Island in sorrow, although they do not know why, and they ride off to find him. They find Patin, then decide to split up to search more widely, and to meet again at King Lisuarte's court.
Gandalin tries to talk some sense into Amadis but fails, and while Gandalin sleeps, Amadis leaves him to wander the mountains again. He rides until he meets a hermit at a spring. He convinces the hermit to allow him to live at the hermitage on an island named Poor Rock, where he can pass what little time remains in his life. Grief is killing Amadis, despite the hermit's counsel to abandon his sorrow as a worldly vanity.
At Amadis's request, the hermit gives him a new name: Beltenebros, which could be translated as "Handsome Gloom."
Gandalin searches for Amadis and meets some damsels who had found his armor, which Amadis had abandoned at the spring when he left with the hermit. A knight named Guilan the Pensive has taken the armor to King Lisuarte's court. Gandalin resumes his search.
Durin tells Oriana how her letter made Amadis want to die. She faints with sorrow and guilt, but soon sends the Damsel of Denmark to Scotland to look for Amadis, thinking he would go there to see his foster father. If the Damsel finds Amadis, she will tell him to meet Oriana at her castle, Miraflores. But the Damsel does not find him.
Sir Guilan the Pensive meets an evil knight on his way to King Lisuarte's court, defeats him in a perilous adventure, and continues on to the court to deliver Amadis's arms to the Queen. Everyone is distressed at their sight and wonders what has happened to Amadis.
While Beltenebros is at the hermitage at Poor Rock, he composes a sad song. He knows that he is faithful and that Oriana is wrong, but he will obey her at the cost of his life.
One night, he hears damsels singing, and discovers that his brother Florestan's lover, Corisanda, has stopped there on her way to King Lisuarte's court to look for Florestan. He teaches the song to her damsels before they leave.
When Corisanda arrives at the court, she tells about meeting the sad Beltenebros, and Oriana and her friends realize that he is Amadis.