Granted he should've listened to his prince's orders, Arthur did the last thing expected of him — he disobeyed.
It was beyond madness to take away the daughter of the Lord Paramount over some prophecy, it was even more mad when Lyanna herself agreed to going with Rhaegar.
He'd chalked it up to it just being another one of his dear friend's jokes, expecting the prince to start laughing at some point and explain to him it was all only in jest, to see if Arthur would willingly put his loyalty above his sense of rightfulness.
When the dragon prince didn't laugh, however, Arthur was quick to deny him. It was the first and only time he disobeyed orders from a member of the royal family, because there would be no more orders to be disobeyed.
He had made up his mind in a matter of seconds after he shut the door on his prince's face, and then he was quickly pulling on whatever clothing he could find that would fit inside a satchel and a bag. Arthur needed to be quick, he needed to cover up all of the traces that he had once been inside that room in Harrenhal.
One look at Dawn, poised next to a wall, and he knew he wouldn't even dare leave the sword he had earned by right. Perhaps some day he'd find the courage to step foot in Starfall once more, just to return his family's sword.
That day would probably never arrive.
Arthur peeked outside of his chambers moments after he was done with packing up his belongings, Dawn wrapped in leather and cloth behind his back, though the longsword would certainly bring attention nonetheless, and then he was setting off across the hallways.
He didn't dare knock, afraid he'd wake up someone else or draw unnecessary attention. He was quick to enter your bedroom, his eyes setting on you almost as if on instinct.
"We need to leave. Now."