Free The Light Fantastic by Terry Pratchett

Grandad.”
    Rincewind looked around cautiously, listening for the sound of a rogue troll. He’d seen what normal trolls could do to a forest. They weren’t naturally destructive, they just treated organic matter as a sort of inconvenient fog.
    “Let’s hope he doesn’t find it, then,” he said fervently.
    Kwartz sighed. “Not much chance of that,” he said. “They’ve lit it in his mouth.”

    “It’sh a judgeshment on me!” moaned Cohen. He tugged ineffectually at his bonds.
    Twoflower peered at him muzzily. Gancia’s slingshot had raised quite a lump on the back of his head and he was a little uncertain about things, starting with his name and working upward.
    “I should have been lisshening out,” said Cohen. “I should have been paying attenshion and not being shwayed by all this talk about your wosshnames, your din-chewers. I mussht be getting shoft.”
    He levered himself up by his elbows. Herrena and the rest of the gang were standing around the fire in the cave mouth. The Luggage was still and silent under its net in a corner.
    “There’s something funny about this cave,” said Bethan.
    “What?” said Cohen.
    “Well, look at it. Have you ever seen rocks like those before?”
    Cohen had to agree that the semicircle of stones around the cave entrance were unusual; each one was higher than a man, and heavily worn, and surprisingly shiny. There was a matching semicircle on the ceiling. The whole effect was that of a stone computer built by a druid with a vague idea of geometry and no sense of gravity.
    “Look at the walls, too.”
    Cohen squinted at the wall next to him. There were veins of red crystal in it. He couldn’t be quite certain, but it was almost as if little points of light kept flashing on and off deep within the rock itself.
    It was also extremely drafty. A steady breeze blew out of the black depths of the cave.
    “I’m sure it was blowing the other way when we came in,” whispered Bethan. “What do you think, Twoflower?”
    “Well, I’m not a cave expert,” he said, “but I was just thinking, that’s a very interesting stalag-thingy hanging from the ceiling up there. Sort of bulbous, isn’t it?”
    They looked at it.
    “I can’t quite put my finger on why,” said Twoflower, “but I think it might be a rather good idea to get out of here.”
    “Oh yesh,” said Cohen sarcastically, “I shupposhe we’d jusht better ashk theesh people to untie ush and let us go, eh?”
    Cohen hadn’t spent much time in Twoflower’s company, otherwise he would not have been surprised when the little man nodded brightly and said, in the loud, slow and careful voice he employed as an alternative to actually speaking other people’s languages: “Excuse me? Could you please untie us and let us go? It’s rather damp and drafty here. Sorry.”
    Bethan looked sidelong at Cohen.
    “Was he supposed to say that?”
    “It’sh novel, I’ll grant you.”
    And, indeed, three people detached themselves from the group around the fire and came toward them. They did not look as if they intended to untie anyone. The two men, in fact, looked the sort of people who, when they see other people tied up, start playing around with knives and making greasy suggestions and leering a lot.
    Herrena introduced herself by drawing her sword and pointing it at Twoflower’s heart.
    “Which one of you is Rincewind the wizard?” she said. “There were four horses. Is he here?”
    “Um, I don’t know where he is,” said Twoflower. “He was looking for some onions.”
    “Then you are his friends and he will come looking for you,” said Herrena. She glanced at Cohen and Bethan, then looked closely at the Luggage.
    Trymon had been emphatic that they shouldn’t touch the Luggage. Curiosity may have killed the cat, but Herrena’s curiosity could have massacred a pride of lions.
    She slit the netting and grasped the lid of the box.
    Twoflower winced.
    “Locked,” she said eventually. “Where is the key,