"Boom!"
The obstacles blocking the doorway were blasted away, and the young wizards under the Imperius Curse filed in.
"Go!"
Audrey hesitated no longer. She pushed Harry into the pipe and followed him, sliding rapidly downward.
"Ahhh-!" Harry screamed in terror.
The intense sensation of falling sent Audrey's heart racing. She did her utmost to keep herself from being afraid, ready to fight at any moment.
The pipe twisted and turned, winding around and around as though it had no end.
Several minutes later, Harry suddenly disappeared ahead of her, followed by a cry of "Ouch!" Then Audrey landed on the damp ground with a splat, covered in black sludge.
She gritted her teeth and climbed to her feet. "Lumos."
The light at the tip of her wand dispelled the darkness in the tunnel, but still could not illuminate very far. Audrey swung her wand sharply. "Incendio."
A searing flame shot down the tunnel, briefly illuminating everything. Only then did she see that before her lay a dark stone tunnel large enough to stand in.
"Oh my God."
Harry struggled to shake the muck off his hands. "We must be miles beneath the school! Ugh, this is disgusting."
"Scourgify."
The mud on both of them vanished.
"They won't follow us, will they?"
Harry looked back and asked anxiously.
"I don't know, but all we can do now is go forward."
They walked single file through the muddy tunnel, each step making a splashing sound that echoed endlessly. Every so often, they cast Incendio to scout the way ahead.
The good news was that they encountered no danger along the way.
The bad news was that they rounded bend after bend, and the tunnel seemed to have no end.
"Hermione... why did she turn out like that?"
Harry asked quietly.
"I