Chapter Text
Chapter 1 - The First Step
What does it take to kill a man?
If you're stronger than him, a straight fight is enough. Grip his throat, pin his chest, drive the blade into his heart, clean and done.
But if you're still young and he's in his prime, you need a little more than that. You need a knife no one can see. You need a moment where no one dares ask why. You need a reason that makes everyone who sees the body simply nod and say: he deserved it.
Aven Karstark spent an entire year finding that knife.
A year ago, he woke up in this body. No omen, no divine vision, no face in the flames. Just a wrenching pain in his chest, like someone had seized his heart and twisted, and then darkness. When he opened his eyes again, the ceiling was unfamiliar. The air was unfamiliar. Even the way he breathed felt wrong.
He lay there for a long time.
The face in the mirror had short brown hair and gray-blue eyes, the jaw still carrying the unfinished softness of a teenager. The boy in the mirror looked at him. He looked back. No screaming. No fainting. He didn't even reach up to touch his own face to confirm it was real. He just looked — for a very long time — like a drowning man who finally breaks the surface, only to find, before he can even feel relief, that he doesn't recognize this sea.
Two sets of memories were crammed inside his skull.
One belonged to a man named Chen Wei. Thirty-five years old. HR manager at some company, working late every night, whose greatest skill was saying "this is the company's decision" with enough sincerity during layoff meetings to almost believe it himself. The last frame of that memory was a hallway with flickering lights, someone crying, blood pouring from a wound in his chest, heat running down along his collarbone. He wanted to say: I didn't make the list. His throat tasted like rust.
The other set belonged to a sixteen-year-old boy. Aven Karstark, third son of Rickard, Lord of Karhold. That memory was quieter. Sword drills, meals, sleep, walking with his head down through the castle corridors, doing everything he could to avoid being noticed.
The two sets churned together like two colors of ink poured into the same cup. Murky. Dark. Nothing clear.
The first few days, he thought he'd gone mad. Or that he was dreaming. Or that his brain, in those final seconds in the hallway, had invented something long enough to fill the dark. He pinched his own arm until it bruised. The pain was real. He tested the serving women, small talk, castle gossip, questions about Winterfell and House Stark. Every name they said, he already knew. Eddard. Catelyn. Robb. Sansa. Arya.
Names he had watched on a screen across eight seasons, now spoken from another person's lips. Like nails hammered one by one into a coffin lid.
A Song of Ice and Fire.
This world had dragons, magic, White Walkers beyond the Wall, and the fire of a red priestess. But mostly it had power, schemes, and betrayal. No matter how important a person was, the next second they could be dead under someone else's calculations. Eddard Stark would die. Robb Stark would die. Joffrey would die. Tywin would die. Everyone would die.
And Aven Karstark, a character with no name in the source material, the third son of House Karstark, not a single line of dialogue to his name, didn't even count as a piece on this board.
He spent 3 days accepting that. Then another month untangling the two memories, pressing Chen Wei down into the deepest layer of his subconscious, making himself fully into Aven Karstark. After that, one question remained.
How do I survive?
The answer was simple. To survive, someone else has to die first.
The Karstarks were a cadet branch of House Stark of the North. The family's fate played out clearly in his memory. During the War of the Five Kings, Lord Rickard Karstark would kill Lannister captives seeking revenge for his slain second son Torrhen, and Robb Stark would execute him with his own hand. Harrion, the eldest, would rot in a southern prison and never come home. Torrhen would fall on some battlefield. And the lord's own brother — Arnolf Karstark, would seize Karhold in the chaos, betray the Starks, defect to the Boltons, and eventually be purged.
Aven wasn't going to let any of that happen.
His first move, once he'd learned his way around the castle, was to keep his eyes on Arnolf.
As for evidence, from day one, Aven had never planned to solve this problem by gathering any.
If Arnolf had actually done those things, good. If he hadn't? Even better. Rumors in Karhold didn't need truth. They only needed direction. Any misfortune, any unexplained loss, anything that had no business being inside the castle, all of it could be pointed at the lord's own brother. Rumors were water. They ran downhill, toward whatever was easiest to drown. Aven only needed to give the current a gentle push.
Today, the wind and snow over Karhold were particularly fierce.
Rickard had taken his heir Harrion to Winterfell for the customary annual visit, territory reports for Lord Stark, and a few cups of hot wine in the cellars if they were lucky. Torrhen had been hammering away on the training yard all morning until he was soaked through, then retreated to his room to sleep off the effort. He knew nothing of what was happening in the castle.
The power of Karhold rested, for the moment, in Aven's hands.
That morning, a rumor began moving through the castle. The lord's own brother, Arnolf, was planning to betray his brother and seize Karhold while the lord was away. It spread fast, kitchens to stables, stables to the market, even the washerwomen were talking. No one knew where it had started. Everyone had heard it.
At midday, Karhold's soldiers "happened" to discover a sizable cache of weapons in Arnolf's quarters. Swords, axes, spears, and one heavy crossbow. A heavy crossbow was siege equipment. Commoners in Karhold weren't permitted to own one. It had no business whatsoever sitting in a cadet-branch noble's private rooms.
The soldiers carried everything out to the castle courtyard and stacked it in a pile where all could see.
By afternoon, the great hall of Karhold.
Aven stood at the far end of the hall. Not in the lord's seat, that wasn't his yet. But he stood above everyone in the room because he was the acting lord of Karhold, and his position, one step below the high seat, still placed him above every man present. The braziers burned red, making the sigil on the wall appear to shift and twist. Household retainers lined both sides of the hall, faces arranged in various degrees of unease, some blank, some frowning, some with eyes fixed firmly on the floor.
Arnolf was held in the center of the hall by two soldiers. His clothes were smeared with mud, his cuff torn open, his hair loose and tangled, nothing like the neatly dressed cadet-branch nobleman he usually was. His chest rose and fell in hard, rapid surges. He breathed like an animal that had just been caged.
The right time. The right reason.
That was all it took to kill a man cleanly.