Gaius looked up from his book when Merlin came in. "Did you get me the hemlock I asked for?"
Hemlock. "Ah, no, sorry."
"What do you want hemlock for? That's poison," the Doctor noted.
Gaius frowned. "Who's this?"
The doctor seemed to have no intention of introducing himself. He had his hands clasped behind his back innocently and was examining a shelf of supplies.
"Uh, this is the Doctor," Merlin said, unsure.
"The village doctor?" Gaius clarified.
"No," Merlin replied.
"Where is he from, then?" Gaius closed his book and placed it on the table.
"I... I don't know," Merlin admitted.
"Here, there, nowhere," the Doctor said, "I'm a wanderer."
"Why is he here, Merlin?" Gaius asked.
"I found him in the woods," Merlin explained. "He had this magic box—"
"I already told you, it's not magic," the Doctor said indignantly, shaking his head. "Magic is what people call things they don't understand."
It was Merlin's turn to be indignant. "Yeah, well I don't understand your box," he said testily, "And neither will the king if he finds it. I don't care what it really is, if he sees it he'll think it's magic, and you're a dead man."
"Maybe," was the Doctor's only response. Then he went back to looking through their supplies, this time picking jars up to examine.
Gaius gave Merlin a questioning look, which Merlin answered with a shake of the head. "He's not from around here."
"Obviously," the elderly physician replied.
"Ooh," the Doctor lifted a jar of liquid up to the light. "Now this is interesting."
"Put that down!" Merlin yanked the jar out of the surprised Doctor's hands. "This is serious!"
"Is it now?" The Doctor smiled.
"Are you dense?" Merlin hissed, not wanting to yell.
"I dunno, are you?" The Doctor asked. He didn't let the flabbergasted boy say anything before he continued. "The Merlin, eh?" He circled the boy, as if to examine him from every angle. "Let's see what makes you tick."
"Excuse me?" Merlin exclaimed as the Doctor reached into his pocket and pulled out what looked like a metal candlestick and held it up to this head. The candlestick glowed blue at the tip and made a high whistling noise.
"Put that away! Do you want to get us both killed?" Merlin exclaimed.
"Interesting," the object's whirring seemed to be telling the Doctor something.
"You are the most careless sorcerer I've ever met!" Merlin threw his hands up and walked away.
"I'm not a sorcerer, I'm the Doctor," said the Doctor, following Merlin and waving the candlestick aroug the boy's head. "Stand still!"
"What is that thing anyway?" Merlin's curiosity got the better of him for a moment.
"Sonic screwdriver," the Doctor answered.
"A what?"
It was no use asking, the Doctor wasn't listening anymore. He had finished pointing the thing at Merlin and was now waving it up and down the room. He started walking around with it pointed at the floor.
"That's not normal," the Doctor muttered. He turned to Gaius, who had been watching the exchange with fascination. "What's below us?"
"The Vaults," Gaius answered.
"Anything down there you would describe as magical?" The Doctor emphasized the last words by miming something glowing with his hands.
"Well, yes, Uther has several magical items kept out of reach," Gaius said.
"Ah," the Doctor nodded. He held up the sonic screwdriver. "You see one, or some, or all of them, are giving off some readings that I wouldn't expect to see on Earth this century. Any century, actually," he broke off, eyebrows furrowed, staring at the sonic. "In fact, it looks an awful lot like—"
The Doctor was cut off when the door opened again and the dark face of Gwen appeared.
"Hallo," the Doctor waved cheerfully.
"Merlin, the king requests your presence immediately," Gwen looked looked nervous. "You and your Stranger."
It took a minute for the Doctor to realize that they were looking at him. "Oh, that's me."
"Yeah," Merlin said, "I don't make a habit of bringing home strays."
"Funny, I do," the Doctor said. He tucked his sonic screwdriver safely back in the inner pocket of his jacket. "Let's go, then. I'd very much like to meet this King of Camelot."