In the days after her return, the princess spent an unexpected length of time with her cousin the Princess Rhaenys and Lord Corlys Velaryon. The three resumed plotting a way to use Alysanne to trap Aegon, even though Queen Rhaenyra had refused the idea before. The murder of Prince Lucerys had only served to further convince Princess Alysanne that something needed to be done urgently. They could not merely summon their allies and wait to strike. If she could help capture or kill Aegon, it would prevent the needless deaths of thousands. It was more than worth it to put herself in danger for a chance like that. Her husband was aware of her plotting but did not support her plan to endanger herself. He had made an oath the morning of their wedding day to protect her from Aegon. Even if it made sense to put her in danger strategically, to do so would go against that oath.
When the Princesses Rhaenys and Alysanne presented their new plot to Queen Rhaenyra, they were well prepared for any questions their sovereign was like to ask. They would have Alysanne make an appearance in various small villages in the Riverlands, meeting with the smallfolk and consoling them about the fears and financial woes the coming conflict would bring to the whole of Westeros. Princess Rhaenys would trail her on Meleys, staying out of sight. Silverwing would also be present but kept in a field outside the town under the pretense that the dragon scared the smallfolk. In reality, they were simply trying to invent an opportunity that would seem perfect to Aegon. If Silverwing were a short run away, Alysanne would be quite capable of mounting a resistance and Aegon would not think it safe to come. Once Sunfyre had been spotted, Princess Rhaenys would take to the skies and direct Silverwing Alysanne's way. On their two dragons, both much older and larger than Aegon's Sunfyre, the Princesses would be able to apprehend him easily. It was with great hesitancy and out of great respect that Queen Rhaenyra gave her consent. Though the Queen disliked the idea of sending more members of her family into danger, Rhaenys and Alysanne were adult dragonriders and would be able to watch each other's backs. With the death of her beloved son Lucerys, removing Aegon and his claim became a pressing matter and the Princesses' plan was a reasonable one.
Before leaving, Princess Alysanne told her husband of the Queen's decision and assured him that she would be alright. This was a decision she was making with full knowledge of the risks for the sake of the realm, for him, and for their nephews. The two boys were quite sad to bid farewell to their beloved aunt-whom they called their "mother" more oft than not-and listened well when she told them to behave honorably in her absence.
The year 129 AC, when Alysanne and Rhaenys Targaryen set their trap, was one of autumn. Farmers throughout the Riverlands were toiling to plant and harvest their last crops before the coming winter. Princess Alysanne found the smallfolk to be very wary and seeking reassurance that there would be no further conflict between members of her house. The previous summer had been a short one and food would be sparse once the cold hit. Soldiers required more food than the average man and fielding an army would cause significant strain on their meager grain stores. This worry, a very valid one, was further motivation for the princess. A war between dragons would not simply hurt the members of her House, its effects would ripple throughout the Seven Kingdoms.
Princess Alysanne was merely four days into her visits with the smallfolk of the Riverlands when Aegon appeared in the skies above atop Sunfyre. The golden beast was rendered all the more dazzling and terrifying by the storm clouds above the village. When lightning struck, Sunfyre's scales reflected its shining light.
After spotting the dragon's shimmering scales in the darkness, Princess Alysanne began to run for her Silverwing. She was stopped by a dragon's roar. It was too deep to belong to Sunfyre. She searched the skies frantically, thinking, perhaps, that Meleys had come to her rescue more quickly than she'd expected. But the second dragon in the sky was not red. It was Green.
The Princesses Rhaenys and Alysanne had anticipated that when King Aegon came, it would be against the advice of his small council, who would not want him to endanger himself. He would have chosen to go to Alysanne despite this heeding. He was an impulsive young man known for his ability to navigate the tunnels within the Red Keep. All signs pointed to his pursuit beginning with an escape.
The only two other dragons possessed by Aegon's supporters were Dreamfyre, Helaena Targaryen's mount, and Vhagar, who had been claimed by Prince Aemond. Queen Helaena was a gentle spirit and not the most present of mind. Only a fool would expect her to ride her dragon into combat except in the most dire of situations. Aemond, on the other hand, was a more practiced warrior than even his brother and had newly become the only living man to survive dragon-on-dragon combat. Still, the princesses had not even considered that he might join his brother on his flight to the Riverlands.
Prince Aemond had resented his older brother since they were children for his cruelty and his superior claim to the throne. Further, he had always respected and loved his older half-sister, Princess Alysanne. She couldn't imagine that the little boy she'd taught to read the histories could aid Aegon in capturing her. But, as Lucerys' death had proven, Aemond was no longer that little boy. He was the rider of Vhagar and one of the most vicious men in the realm, second only to his older brother, and he had come to resent his older sister in recent years. Friends and servants of the prince have attested that the suffering of his sister, Helaena, in her role as Aegon's wife bothered him deeply. He felt that in allowing Helaena to take her place, Alysanne had selfishly betrayed their family. Princess Helaena Targaryen was a peaceful young woman and easily frightened. She was unable to moderate Aegon's impulses and manipulate him for the good of the realm in the way that Alysanne likely could have. Prince Aemond believed that Princess Alysanne herself was to blame for the conflict between the two branches of House Targaryen as her choice to marry Ser Walter Tully had prevented them from being united and brought Aegon to his darkest place yet.
One could imagine that when Princess Alysanne heard Vhagar's roar, she realized she only had three options. She could attempt to flee on Silverwing, abandoning Princess Rhaenys and the people of the village to suffer Aegon's wrath. She could fight her brothers, a choice that would surely lead to bloodshed. The princess was no coward, but she was pragmatic. As a woman, she had never been given the same opportunities to study combat that her brothers had enjoyed. The Targaryen dragons were something of an equalizer on that front. No army would reject the aid of a dragon simply because its rider was a woman. But in a fight against another dragonrider, the advantage Silverwing gave her would be gone. Especially when one of the opposing dragons was Vhagar. Silverwing was not Arrax. Princess Alysanne's dragon would not be an easy kill for Vhagar, but she would be no fair match.
It was for the sake of her beloved dragon and for her brothers and cousin, who may well have died if Alysanne rode Silverwing into combat, that she chose her third option. Princess Alysanne stayed on the ground and waited to meet her fate, which she had spent so many years avoiding. Aegon soon landed on Sunfyre and abducted his sister, tying her hands for safety and placing her behind him on Sunfyre's golden back. In her later years, Princess Alysanne often remarked that she should have flung herself from the dragon's back as it ascended. Doing so would have saved her significant pain.
As Sunfyre rose back into the storm, Meleys appeared as well. Princess Alysanne shouted for her cousin to flee but the Princess Rhaenys either did not hear her over the rain and thunder or chose to ignore her message. Meleys swooped with her jaw open towards Sunfyre but the dodged the blow and sent the older dragon flying straight towards Vhagar. With a signal to Prince Aemond, Aegon fled the fight for King's Landing. Vhagar was more than capable of dispatching with the Red Queen on her own, especially as Silverwing, likely confused by the storm, had not risen to join the fight.
When Princess Alysanne Tagaryen returned to the Red Keep she was not treated as a prisoner nor a princess of the realm. She was kept confined to her rooms, the same she had stayed in as a child, except for meals and some meetings with her family and the crown's interrogators. She was careful to protect her sister's secrets and claimed that she had not been allowed into Rhaenyra's small council meetings. On what matters she could not feign ignorance, she told lies. All the while, she carefully plotted how to send her sister what secrets she was learning in her time in King's Landing. Even the interrogator's questions could be helpful clues to Aegon's plans and she was careful to jot them down after each meeting and to hide her notes in a secret place.
Once Aegon had brought the princess to King's Landing, there was not much his mother and grandfather could do to prevent him from taking her as a second wife. Aegon's small council had been forced to temper his impulses on many occasions and it was decided that this was one matter they could support him on. Attaching Princess Alysanne to his claim strengthened it and cast suspicion on Rhaenyra and House Tully, as it would raise questions about why Alysanne would betray them. The Dowager Queen Alicent used her connections in Oldtown to have the High Septon set aside Princess Alysanne's marriage to Ser Walter on the grounds that they had no children to prove consummation, so her son would be free to take her to wife.
Princess Alysanne herself mounted little resistance to the marriage. She had expected it from the moment she saw Vhagar overhead in the Riverlands. Further, she suspected that once they were married, she could convince Aegon to trust her with more important secrets and that she would have enough access to the palace to find a way of delivering her messages to Dragonstone. Neither did Queen Helaena seem much bothered by the prospect of her husband taking a second wife. When asked about the matter, she often said that she looked forward to the wedding as, afterward, there would be another woman sharing her burdens.
As a wedding gift to his new bride, King Aegon returned Princess Alysanne's dragon to her. He had sent the dragonkeepers to retrieve the beast and had convinced his council that his queen should be allowed to ride her own dragon, with the stipulation that she must be accompanied by either Prince Aemond and Vhagar or the King and Sunfyre when she did so.
Though King Aegon's wedding to Princess Alysanne was nearly as rushed as his wedding to Queen Helaena had been, it was significantly grander. The King wanted the ceremony to be a showing of strength that would overshadow even Alysanne's first wedding at Riverrun, which had seen over a hundred lords in attendance.
In preparation, he commissioned a massive statue of Silverwing and the two Alysannes as well as one of himself standing with King Jaehaerys. The addition of the Old King likely came at the suggestion of the Hand who remembered how beloved King Jaehaerys had been and who was well aware of the Old King's support of male primogeniture. The statue, and the warm way it depicted Jaehaerys looking upon Aegon, almost seemed to suggest that if the Old King had been in his grandson Viserys's position, he would have chosen Aegon as his successor.
Of the previous Targaryen kings, however, Aegon's actions in 129 AC mirrored those of Maegor the Cruel's the most closely. Many scholars have compared Prince Alysanne Targaryen to Maegor's three Black Brides, though she wasn't a widow. The Lord Hand Otto Hightower had attempted to convince his grandson to put an end to Ser Walter Tully before wedding his bride. Even with the High Septon's support, many of Aegon's supporters were disgusted by the idea that their king had stolen another man's wife. King Aegon, in his cruelty, declared that Ser Walter Tully should live so that he could feel some measure of the pain Aegon claimed he felt during his beloved's marriage to the riverman.
After King Aegon took his elder half-sister to wife, Ser Walter did face significant struggles. He had relocated to Harrenhal to lead his fellow rivermen, as his grandsire had only become more ill during the journey east, but had left his beloved nephews on Dragonstone for their safety. Many among his bannermen had urged him to invade King's Landing and reclaim his wife before the ceremony. Ser Walter, however, trusted the Princess to make use of her situation and knew that any attempt at rescue would likely end in the death of his men in dragonfire. Queen Rhaenyra was still short on allies in 129 AC and desperately needed the sizable army of the riverlands backing her. Every man lost in a battle for Alysanne would be a man not there to fight in the greater war that was surely coming and there were already whispers of infighting between the rivermen. Lord Blackwood had accused his family's long rival, House Bracken, of secretly pledging allegiance to King Aegon and young men from each house had begun attacking each other late at night in the halls of Black Harren's keep.
Queen Rhaenyra herself was enraged by the wedding and questioned why her younger sister would even say the vows. It, perhaps, would have been more honorable to face the King's Justice than to betray her Queen and her beloved husband in one fell swoop. On a practical level, the Princess' failed plot had cost Rhaenyra two adult dragons. Silverwing was now confined to the dragonpit in King's Landing and Meleys the Red Queen had yet to be seen since her battle with Vhagar. Princess Rhaenys had been similarly lost. Where Rhaenyra's cause had once held eight dragons to Aegon's four, they were now down to five. Though they still held superior numbers, all of Aegon's dragons were adults and one was Vhagar. Of Rhaenyra's five, three belonged to children and none were as large as Vhagar or even Silverwing. Prince Daemon encouraged the queen to send their remaining dragons to King's Landing before they lost what upper hand they still held, hoping that if they did so Silverwing might rise to join them. Rhaenyra denied her husband's request, unwilling to risk her two remaining young sons for the sake of her "traitorous sister."