Season One…

Arthur watched from the balcony above as Merlin burned. His screams filled the air and Arthur's insides felt a little sick. Merlin was the beginnings of a friend, not just beginnings if he was being honest with himself. The betrayal was like a knife in Arthur's gut. Merlin had magic. It still sounded wrong. Merlin wasn't evil! But he was, the evidence laid before his eyes. So Arthur watched the sorcerer burn with cold satisfaction as a part of his heart died.

Season Two…

After everything that had happened, after everything they had been through and it'd come down to this. This moment. Arthur had seen Merlin's magic. Now the sorcerer stood frozen as he watched the expressions flash across the Prince's face. Surprise. Hurt. Betrayal. Anger. Rage. There was much shouting and pleading that followed, but the pleads fell on deaf ears. Arthur did his duty and dragged Merlin to his King. He did as he was ordered and locked him in the cells. But as Merlin was executed Arthur found his sense of duty fail him. He could not watch. And if Merlin was still watching Arthur's expressions he would have seen two more. Sorrow. Regret.

Season Three…

First Morgana, now Merlin. How could Arthur have been so blind? His father's mind lost in madness he had no one to turn to. No solid rock. Now it was all on him. He was so tired, his heart a right up mess. He couldn't deal with this right now. Not when he needed his friend most.

"Go."

It was a simple order. But then Merlin had never been good at following orders. He tried to protest. Arthur wasn't having any of it.

"GO! If you EVER return you will be killed. Go NOW!"

And so Merlin fled. Arthur never really knew why he didn't follow the law. Why Merlin didn't die that day. Nor why he lied to everyone and Merlin became one of the many lost in Morgana's reign. All he knew was that he couldn't kill Merlin and later he'd regret it.

Season Four…

Arthur stared. He couldn't wrap his mind around it. Merlin had what? How is this possible? When did this happen? Why hadn't Arthur stopped it? Merlin was talking. Talking fast. Explaining. Arthur's numb mind couldn't make sense of the words. So he turned his back on Merlin and walked away. Later there would be shouting, tears and friendships slowly beginning to mend. But not now. Now, Arthur couldn't deal. So he didn't. He just walked away.