For the first time Wilbur saw the whole thing. Until now he had entertained a faint hope that Merlin might not really want his eye. But this was the clincher. The _Elixir of Caution_! Desperately he cast about for a means of escape. There was none. And Merlin was watching him with an eagle eye. "Maybe," Wilbur offered weakly, "a few drops of my blood would do the trick. You don't want Arthur to get _too_ timid." "Nice of you to think of it," Merlin said. "But I really couldn't fool with that recipe." Wilbur wished with all his heart that he had the courage to put up some kind of fight. Merlin was an old and feeble man. But he knew his genetics. Wilbur had been born without a gene of courage. Wilbur rubbed his right eye, the one he would soon be without, and felt tears well up. His last glimmer of hope was borne on a sigh. "Maybe he won't come." "He'll come all right. Arthur never breaks a promise. That's one of his best points. What I'm trying to do is see to it that he isn't so rash about making them in the first place." It seemed that Merlin was right, for just then there came to their ears the sound of iron shod hoofs in the courtyard above their heads. The ceiling trembled slightly and a drop of water fell on Wilbur's head. Then footsteps clattered down a long flight of stairs and the door swung open. It was Arthur, and from his appearance it was plain he had been in a fight. * * * * * From a cut alongside his temple blood dripped. His shirt of mail had been pierced at the left shoulder and blood glistened redly there. Some had trickled down and lay in beads like rubies on the gleaming mail. His face was streaked with sweat and dirt and his hair lay in wet clumps, and he was breathing hard. "What happened?" Merlin asked quickly. Arthur let out a laugh and his eyes glowed fierce. "A band of varlets tried to ambush me on my way here. Had I not been in so great a hurry to keep my appointment with you I'd have brought you some heads on Excalibur's point." He held up the great sword and Wilbur turned faint at the sight of the gore along its blade. He put his hand over his mouth and his eyes rolled upward. "Wipe that blade before this one perishes of fright," Merlin said quickly. Then he became solicitous. "Are you sore wounded?" "There were only ten," Arthur laughed. "They were too busy defending their lives to do me much harm. Now, where is that drink you invited me here for?" "It will take a while to prepare," Merlin said. He busied himself with a kettle and some jugs and powders. Wilbur was turning a pale green from fright. He had to think of something. Suddenly he turned to Arthur. "You won't like this drink," he whispered urgently. "It may even poison you!" Arthur stared down at him. "Even so I needs must drink it. I have given my word. A promise may not be broken."