"You're not my usual dentist," observed Gumm as he walked in. "Where's Dr O'Cane?"
The stranger in the surgery was small, elderly and without a visible assistant. He bowed his grey head while ushering Gumm to the chair. "Something most unfortunate," he said. "Dr O'Cane has been called away at short notice. He hopes to be back very soon."
"I've never even seen you before," said Gumm, perching on the edge of the chair.
The little man smiled. It was an apologetic smile, though white and brilliant to a degree Gumm supposed he ought to find reassuring. "If you would prefer it," Dr O'Cane's replacement said, "you can make another appointment for twenty-eight days hence. He may possibly be back by then."
With a snort of impatience, Gumm swung up his legs and lay back in the chair. The elderly man switched on the searchlight and steered the beam straight into Gumm's eyes. "There we go," he murmured as Gumm tried to blink away the fireworks. "Open wide, please."
Gumm complied, and the dentist and his implements loomed and poked. The old man's eyes were blue and benign like an escaped war criminal's, and he murmured to himself while his probe and mirror rattled around Gumm's mouth.
"Hm, yes, yes indeed ... ah, yes ... hmm. Yes, I see. Hm, very good, yes." It was, Gumm thought, like listening to the wrong end of a very dull telephone conversation.
At last Gumm was permitted to sit up and rinse while the dentist scribbled in his notes. Then he turned and flashed his white smile again. "I see from your notes," he said, "that you were not due a routine check-up for another four months. Yet everything appears to be in reasonably good condition. What seems to be the problem?"
"I'm not sure," said Gumm. "It just doesn't feel right in there lately."
"Any discomfort?" asked the old man. "Pain?"
"No, there's no pain and there isn't exactly any discomfort. There's a taste..."
"What kind of taste?"
"I can't identify it," said Gumm, "but it isn't very pleasant. Not strong, but it's there all the time, as though my mouth were bleeding inside. It doesn't taste much like blood, though. And it isn't like anything I've ever eaten, either. It's more ... chemical."
"Like a mouthwash?"
"No, more as if I'd eaten something artificial, something not meant to be eaten. It's sort of synthetic and greasy, like soft plastic."
"Any other symptoms?" asked the dentist.
"I don't know if you could even call it a symptom," said Gumm. "The inside of my mouth feels - well, strange. As if the tongue's the wrong size or some of the teeth aren't in their proper places."
"But without any pain?"
"Well, we'd better have another look then, hadn't we?" As Gumm resignedly settled back again the old man patted him on the shoulder. "It's probably nothing to worry about. Open wide."
After what seemed like several minutes of prodding and mumbling, the dentist abruptly straightened and said, "Stay there a moment, please." He moved away somewhere Gumm couldn't see, particularly as the old man had knocked against the searchlight and beamed it into his eyes again. Gumm heard a rustle of papers and the sound of a drawer opening, then some quiet, steady sounds he was unable to identify.
He was about to sit up when he felt the old man's hand on his shoulder. "Open wide," the dentist said, and Gumm waited for the metal to probe his mouth once more.
Instead, he felt a sharp pain in the side of his left buttock. He resolved to sit up at once and protest the indignity, but the old man was already smiling his apologies. "Just the anaesthetic," he said. "It's often less difficult when the patient isn't expecting it."
"But why inject it there?"
demanded Gumm, slurring a bit. The searchlight was very hot. "That isn't going to do my mouth any good, is it?"
"It was a general anaesthetic," said Dr O'Cane's replacement.
"A general anaesthetic?"
"Just leave everything to me," said the old man. "You have nothing at all to worry about. I've discovered the source of your problem. The reason your mouth is giving you trouble is because it is not your mouth at all. It's mine."
"But I've never even met you before," protested Gumm, though he was sure there must be better arguments. He just couldn't quite think of them at the moment.
"Nevertheless," the dentist said, "I assure you that it is so. No wonder your mouth feels uncomfortable; we're completely different sizes. It just doesn't fit you. All those teeth are mine, and possibly the tongue also. We'll see when we get them all out."
Gumm gurgled indignantly, but the light was like a scorching summer sun overhead, making him want to drop off to sleep; and the last thing he saw before his eyes drooped shut was the apologetic gleam of the dentist's white, plastic smile.