I don't own Narnia or the Pevensies.
Peter kept silent. Behind him, the Head Sorcerer withdrew a flask from his cloak and passed it down through three soldiers to his king, who uncorked it.
Fumbling around quietly in the box, Lucy found the bowstring and worked it into place on one side; Edmund had taught her how to do this and the memory of his nimble fingers over hers guided the loops, rather than her eyes, which she kept on the dais.
"A Promise Potion is the liquid manifestation of one of the most powerful spells a magician can learn in this country," Valin said, lifting the bottle up for everyone to see. "A man who drinks more than a few drops of it and makes an oath will be compelled to keep his word, no matter if it opposes his will. It is quite a useful diplomatic tool. Shall I demonstrate?"
He did not wait for an answer, but gestured one of his guards forward, a young soldier who looked surprised at the summons. He stepped up to his king and saluted, though Lucy thought he looked apprehensive. Valin handed him the flask.
"Drink a mouthful," he ordered. Uncertainly, the soldier obeyed. "Now swear you will climb the wall behind us and walk upon the ceiling."
"But…Your Highness," the man gaped. "That's impossible!"
"I gave you an order!" Valin barked. Cringing, the man looked around for an escape, but there was none.
"I swear I will climb the wall to walk upon the ceiling," he pledged obediently. And for a moment, nothing changed. The soldier handed the flask back to the king and the room (save for Lucy, who now sought to detatch the bow from the quiver) waited in complete silence. Then, slowly, the man's back twitched upright, and he began to fidget uncontrollably, and with a sudden, muffled yell, he took off towards the wall, leaping and scrabbling at the stone to absolutely no effect. The army men stayed stone-faced as they watched the humiliation. The wedding guests laughed.
"Only physical impossibility can force a man under the potion's influence to give up on his word," Valin told them, chuckling cruelly. "And even then…it takes some time. Take the fool away."
As three other soldiers dragged their protesting comrade away from the wall and out of the room, and as Lucy at last withdrew her hands from the box, having done all she could to ready her sister's bow, Valin turned back to her eldest brother.
"So now I make you an offer, Peter, King of Narnia," he said, drawing his sword and eyeing it as if the conversation was of little interest to him. "If you swear a little oath for me, I will spare your worthless life."
"Touch one hair on his head and I swear I will kill you," Edmund snarled, taking an aggressive step forward. "And I don't need any potion to guarantee that."
Instantly, Valin swung his sword and dealt him a sharp slap with the flat of the blade, leaving a red welt leaking blood on his cheek, but the young king barely cried out, and stayed where he was. Peter stepped up beside his brother, placing himself between him and Valin, cool-eyed and calm.
"I will swear nothing to endanger my country," he said quietly, so quietly that Lucy could just barely hear him from her side of the room. "If that means my life is forfeit, then so be it."
"Oh, I'm not asking you to endanger your country," Valin said. "I am merely trying to guarantee a smooth transition between your sovereignty and mine. You will lead my army into your castle and welcome us as guests. Then you will lead your own on a false errand – I'm sure your sister could come up with something, she has quite the silver tongue – and I will announce myself as Narnia's new High King. There need be no danger or bloodshed. Here, I have prepared a statement for you. You need only to read it."
As Valin retrieved a small scroll from his belt, Lucy focused her gaze on Susan, hoping to catch her eye to tell them where her bow was, but kept listening carefully, thinking fast for a next step.
"I will not read it," Peter replied evenly.
Valin laid his sword blade against the High King's bare neck in unspoken threat.
"I should hate to rid Narnia of its only king," he warned, reminding Lucy that he did not know who Edmund really was.
"Better Narnia lose her High King than fall into your hands," Peter said, meeting his brother's eyes for just a moment, just as Lucy caught Susan's, and knew that despite the shock in them, she had gotten her message across. Gritting his teeth, Valin let his sword drop and suddenly thrust the flask up before Peter's lips.
"Drink!" he ordered. Peter eyed him with cold defiance. Letting out a growl of frustration, Valin seized the back of his neck and tipped his head back, forcing the head of the bottle into his mouth. Edmund lunged forward, but the guard behind him threw him to his knees and jerked his bound hands backwards, rendering his struggles useless. When Peter began to choke and swallow involuntarily, Valin pulled the bottle back and corked it, waiting impatiently for him to catch his breath, then again thrust the scroll at him.
"Swear the oath," he demanded. Peter only glared, still coughing a little. "Swear the oath or I will cut your head from your shoulders!"
"Then do so already!" Peter shouted back. "For I will not!"
Valin snarled and lifted his blade to strike, but Edmund wrested himself free, scrambling to his feet and throwing himself in front of his brother, who for the first time cried out in fear. But the blow never fell – Valin stopped mid-swing, seemingly struck by a new idea.
Lucy was, too, but she didn't know how to put it into action. Susan's horn was, after all, hanging from the belt of their deadliest enemy at the moment. But if she could somehow get there…
"Such loyalty you inspire, King Peter," Valin remarked. "I wonder…you care so little for your own life, but perhaps…you would show more concern for the life of one of your subjects. Perhaps we could test your own loyalty, hmm?"
Lucy moved sideways, towards the end of the table closest to the dais. She didn't want to find out what Valin had meant by that. But he was moving again – to her surprise, he drew a short knife from his belt and cut Peter's hands free. A second later, a soldier passed down a familiar blade – Rhindon – and Valin placed it in Peter's grasp, taking a step back. Peter, aside from accepting his sword, did not move; he was not stupid enough to attempt anything while he and his brother were in such a precarious position. Meanwhile, two of the guards had pulled Edmund away again, though he was giving them a hard job of it, and they had to twist his arms back yet further to get him to stand still.
"I can make you a murderer," Valin threatened Peter, stepping behind him and placing a chilling hand on his elbow. He was a powerful man – at his push, the High King was forced to lift up his blade, and out it stretched, until the very tip of it…Lucy's breath whipped out of her body as she remembered the story of Vareth's fall from the throne, the set-up, the witnesses, the murdered soldier…
Rhindon's tip touched Edmund's chest, and the two brothers locked eyes.
"You are willing to die for Narnia," said Valin to Peter, his hand tight on the High King's sword arm, "But are you willing to kill for her?"