After Arthur's repeated questioning and swearing to keep the secret, Lady Nym revealed their plan and goal.
They planned to defeat all five champions chosen by Prince Doran and replace them with five challengers selected by Arianne herself.
In other words, Princess Arianne would use her own capabilities to secure the crown of the Queen of Love and Beauty.
Although it smacked of filial piety gone wrong, one had to admit: if this succeeded, it would not only make Prince Doran lose face but also demonstrate Princess Arianne's capability and influence.
"Which genius came up with this plan?"
"Who else? Arianne." Lady Nym said wearily. "The suitors Uncle Doran arranged for Arianne are simply too much."
"Obara and Tyene think so too."
"Tyene once even helped Arianne try to elope. The target that time was Willas Tyrell, the heir to Highgarden, whom Prince Doran had rejected. But my father caught them halfway and brought them back."
Listening to Lady Nym's narration, Arthur actually knew why Prince Doran always arranged old men as suitors for Arianne.
In the original story, Prince Doran had been plotting to overthrow Robert Baratheon's rule and avenge his sister and her children who died in the Rebellion.
He had sent Oberyn to meet with Ser Willem Darry in Braavos, where they signed a secret marriage pact between Arianne Martell and Viserys Targaryen, witnessed by the Sealord of Braavos.
Because the matter was of grave importance, Doran feared Arianne would leak the secret, so he never told her.
Worried that Arianne remaining single as an adult would arouse the Iron Throne's suspicion, he constantly arranged for her to meet elderly suitors while rejecting all suitable marriage prospects.
Arthur felt that the conflict between Doran and Arianne had little to do with him. Challenging champions in a tourney was standard practice and shouldn't cause too much trouble, so he agreed.
Arthur: "Are you sure that as long as I defeat your father, you can get him to knight me?"
"You also have to stay until the end and become a champion." Lady Nym added.
"Don't worry. My father is like me; he's never been one to stick rigidly to rules."
Clearly, they assumed Prince Oberyn, the Red Viper, would definitely be one of the five champions chosen by Prince Doran to defend Arianne's honor.
"Come, follow me into the room."
Lady Nym blew out the candle and stood up. "I'll tell you about the flaws in my father's jousting technique. It might help you."
Obviously, the "flaws" Lady Nym mentioned were of little help to Arthur in defeating Oberyn—they might have even been counterproductive.
However, Lady Nym later found him a sparring partner familiar with Oberyn's moves and characteristics.
It was none other than Ser Daemon Sand, the "Bastard of Godsgrace," Oberyn's former squire who had been knighted by the Red Viper himself—the bastard every other bastard's mother compared them to.
"Although I was knighted by Prince Oberyn himself and served as his squire for years, I am far from his equal. I cannot fully simulate his strength."
After a day of practice, Ser Daemon Sand tossed his balsa wood lance to his squire and dismounted. "And this is just practice. It differs greatly from real combat."
Arthur nodded to him. "You've helped me greatly. If I still can't win, then it can't be helped."
This is basically an open-book exam. If I still lose, then I'm truly lacking in skill.
Arthur took off his rattan armor, which was covered in white dust—marks from the practice session.
They had coated the tips of the balsa lances with chalk, then charged at each other on horseback, checking the hit locations afterward to make adjustments.
Perhaps because they were both bastards, Arthur and Daemon found they had much in common. After a day of practice, they quickly became familiar with each other.
Arthur invited Daemon to dinner to thank him for sparring. During the meal, he asked, "How did they rope you in?"
"Rope me in?" Daemon smiled bitterly. "Tyene poisoned me."
As if afraid Arthur might misunderstand, Daemon quickly added, "But what they asked me to do doesn't violate my knightly vows, so I agreed to become one of the challengers."
Daemon clearly didn't want to dwell on that topic and asked, "Can you tell me about your armor?"
"Rattan armor, developed by the smiths in my fief specifically for the hot Dornish environment. Made from rattan vines." Arthur chewed on a purple olive as he explained.
"Compared to chainmail and plate, rattan armor ensures coolness and lightness while providing decent protection."
"If you like it, give me your measurements. I'll have them make a set for you later."
Daemon hurriedly said, "I will pay the corresponding cost."
In their practice, when he hit the rattan armor with the balsa lance, he could clearly feel much of the force being dispersed.
Every time, he saw Arthur merely sway slightly in the saddle before steadying himself.
Even with balsa wood, the impact force was real.
The two drank and chatted about their travels. Daemon was very interested in Arthur's journey from the North to Dorne.
"I've never left Dorne in all my life. Perhaps I should go on a journey too, see different places." Daemon sipped the Amber Peach Nectar.
"Free and unfettered. That's one of the few benefits for bastards like us who don't have to inherit family lands."
Arthur raised his cup. "To freedom."
Daemon downed a cup, his face flushing slightly with intoxication. He sighed. "The downsides of being a bastard are many. I once proposed to Arianne. She refused."
"She didn't say why, but obviously, it was because of my bastard status. I know even if she agreed, Prince Doran wouldn't have allowed it."
"But what if? Surely I'm better than those old men. They're too old to even fulfill a husband's duties."
Arthur listened quietly as Daemon recounted his woes. He suddenly felt that Daemon hadn't been poisoned by Tyene, but by Arianne.
"Arianne and I grew up together in the Water Gardens. I..."
So Arthur ate his dinner and ate the gossip, listening to Daemon tell stories about Arianne and their peers.
Finally, Daemon's squire escorted the drunken knight back to his quarters.
In the following days, Arthur focused most of his time and energy on sparring with Daemon. As the tourney approached, they stopped drinking.
Every night, Lady Nym would update him on their plan and progress.
Lady Nym: "We have found seven challengers, including you and Daemon. On the day of the joust, you will conceal your identities as mystery knights and challenge the five champions chosen by Prince Doran."
"Seven people?" Arthur prayed, "May the Seven bless the plan's success."
Lady Nym was eager to share. "Don't you want to hear who they are?"
"No." Arthur shook his head. "I just need to focus on defeating your father. I don't want distractions."
Arthur suddenly felt that Prince Doran's decision to keep the secret marriage pact with Viserys Targaryen from Arianne was very wise.