A/N: This fanfic came off the top of my head and I felt the urge to write it down and post it. This is just a prologue and in the following chapters will go back in time to see what led up to it. The change here is that Lyanna had a daughter instead of a son, whom Ned named Astrid Snow. She takes after her mother's side in looks in all but her eyes. She inherited her father's lilac eyes. So I hope you guys enjoy this!
Tywin heard his son enter his solar, he didn't need to look up from his letter to know it was Jaime. The clanking sound of his armor was confirmation enough for him. He heard the noise come to abrupt stop infront of his desk as Jaime waited for his father to acknowledge his presence.
Tywin took his time, signing the letter he was writing before he rolled it up and swales it with the sigil of House Lannister. He put the scroll aside and finally turned to his eldest son. He was wearing the white cloak Tywin observed with detest but that would change soon enough.
Jaime gazed expectantly at Tywin, tapping his feet impatiently, "You summoned me, father?"
Tywin nodded as heading towards the window in his solar that overlooked much of the Red Keep. He gazed down before he poured himself a glass of wine and took his seat again.
"The Young Wolf has bagged yet another victory." Tywin announced.
Tywin watched Jaime closely as he took in the news, he saw fear overtake him for a moment.
"That's hardly news. Robb Stark has been defeating us on the field for quite some time." Jaime quipped.
"Yes and it's beyond time we taught him a lesson." Tywin growled, "A more personal one."
"The Karstarks have already marched home and Robb Stark has lost the Freys. His fate is all but sealed." Jaime reasoned.
"Edmure Tully is set to wed one of Walder Frey's daughter. He has not lost the Freys yet." Tywin informed, "Sansa Stark is too valuable a hostage to sacrifice and she is also Robb Stark's heir. On the other hand, we have his bastard sister who I have no qualms of sacrificing. Perhaps a public execution would get Robb Stark's attention."
"I am alive because of her and a Lannister always pays his debts. Taking her head would be a poor way to do so." Jaime said coldly.
"That is no concern of mine."
"I won't allow it." Jaime gritted his teeth in anger.
"And I'd like to see you try and stop me." Tywin sneered, "The Kingsguard answer to the king and Joffrey would be more than willing to see Astrid Snow's head on a spike."
Jaime slammed his hand on the table in rage, "I killed one king before and if Joffrey so much as lays a finger on her, I won't hesitate to do it again."
Tywin rose from his chair and circled around the table to face his son, "You would kill your king and nephew for a bastard?"
"For her." Jaime hissed before he seemed to grasp what he had just said, "I owe her my life."
Tywin studied his son for a moment. Tyrion had been right all along, Tywin realised.
"And I do not." Tywin countered, "I've already made my mind."
Jaime stepped back as he held Tywin's gaze, "I'll leave the Kingsguard" Jaime offered desperately, "And I'll take my place as your son and heir, if you let Astrid Snow live."
Tywin had to keep himself from smirking, "Done." Jaime's eyes widened in surprise, clearly having not expected Tywin to agree so fast.
"I will let Astrid Snow live and ensure Joffrey allows the same." Tywin concurred, "You will remove the white cloak immediately and leave Kingslanding to assume your rightful place at Casterly Rock." Jaime nodded with resignation at his words.
Tywin continued, "You will marry Astrid Snow and father children named Lannister and never turn your back on family again."
Jaime listened to his father, mouth agape with incredulity as he registered what his father just commanded of him.
"You want me to marry Astrid?"
Tywin hummed in reply as he went back to his seat.
"But I thought you saw her as a lowly bastard."
"I see Astrid Snow for what she is." Tywin said, "I see her as a suitable bride for my son."
"Why?" Jaime asked suspiciously.
Tywin raised an eyebrow at his son's reaction. Tywin noticed that Jaime did not even protest the match, he simply wanted to know the reasoning behind it.
"Do I have your word or not?"
Jaime considered Tywin's demands for a moment before nodding, "You do."
Tywin nodded in return as well, "And you have mine."
Tywin observed as Jaime visibly relaxed at his words. He inclined his head at Tywin before walking out of his solar. Tywin smirked in triumph the minute Jaime was out the door.
Tyrion had been right, Tywin would give the wretched dwarf that much. In turn Jaime had reacted just as Tywin had expected him to. He had never really intended to execute Astrid Snow, she was too valuable to do so, a fact that the girl herself was unaware of. She was the answer to many of the problems Tywin faced.
For all Jaime's faults, Tywin mused, at least he had the sense to fall in love with the right woman.
A/N: Tell me what you thought of it in the reviews section! Don't forget to follow and favorite as well!