Prompt from wolfangeldeath on LiveJournal- she wanted Merlin/Hardy Boys crossover.
"Merlin," Gwen hissed as they crept down the tunnel. "Gaius is so going to kill us."
"Gaius needs help with this and don't you want to know. Besides, Alice knows and she'll tell him where we've gone," Merlin assured his adoptive sister. Up ahead, a light was on, seeping under the bottom edge of the door.
"If we get in trouble, I'm pointing at you."
"Don't be such a worry wart, Gwen. Don't you want to know what's down here? No one's ever been this far and maybe we can help Gaius find a clue to what was written on the crypt." Merlin edged closer and pressed gently against the door. It opened without a noise, releasing more light. A small, lit torch rested in a bracket on the wall.
"Let's go," Merlin said softly, grabbing the torch and she followed him through the second tunnel, muttering a curse under her breath. It steadily went down, the air around them becoming cooler. Keeping his torch steady, they continue on.
The tunnel stopped abruptly at a door made of strips of metal welded together. Its hinges stick before giving way with a wail that bounces off the wall of the tunnel. Looking around, Merlin and Gwen creep past. The door opens up into a massive cavern and their torch light barely penetrates the darkness.
Suddenly, the wind picks up and a loud thumping noise echoes around the cave. "Merlin, what have you done?" Gwen asks as they flatten themselves against the cave wall. Both can only stare in wonder as a large, winged lizard sails down from up above, a long chain clinking with each flap of its massive wings.
As the cave quiets, Merlin looks to his companion, "Gwen, you realize what this means? There's a dragon under Camelot." The dragon just snorts at his sentence, laying down the rock protrusion in the middle of the cave, tail curling around it as it watches them.