"Perce -- Sirius Black!" said Ron faintly. "In our dormitory! With a knife! Woke me up!" 

The common room went very still. 

"Nonsense!" said Percy, looking startled. "You had too much to eat, Ron -- had a nightmare --"

 "I'm telling you --" 

"Now, really, enough's enough!" 

Professor McGonagall was back. She slammed the portrait behind her as she entered the common room and stared furiously around. 

"I am delighted that Gryffindor won the match, but this is getting ridiculous! Percy, I expected better of you!" 

"I certainly didn't authorize this, Professor!" said Percy, puffing himself up indignantly. "I was just telling them all to get back to bed! My brother Ron here had a nightmare --"

 "IT WASN'T A NIGHTMARE!" Ron yelled. "PROFESSOR, I WOKE UP, AND SIRIUS BLACK WAS STANDING OVER ME, HOLDING A KNIFE!" 

Professor McGonagall stared at him. 

"Don't be ridiculous, Weasley, how could he possibly have gotten through the portrait hole?

" "Ask him!" said Ron, pointing a shaking finger at the back of Sir Cadogan's picture. "Ask him if he saw --" 

Glaring suspiciously at Ron, Professor McGonagall pushed the Portrait back open and went outside. The whole common room listened with bated breath. "Sir Cadogan, did you just let a man enter Gryffindor Tower?" "Certainly, good lady!" cried Sir Cadogan.

There was a stunned silence, both inside and outside the common room. 

"You -- you did?" said Professor McGonagall. "But -- but the password!" 

"He had 'em!" said Sir Cadogan proudly. "Had the whole week's, my lady! Read 'em off a little piece of paper!" 

Professor McGonagall pulled herself back through the portrait hole to face the stunned crowd. She was white as chalk.

 "Which person," she said, her voice shaking, "which abysmally foolish person wrote down this week's passwords and left them lying around?" 

There was utter silence, broken by the smallest of terrified squeaks. Neville Longbottom, trembling from head to fluffy slippered toes, raised his hand slowly into the air.

Groaning loudly, Amelia slid down the wall of the staircase. "Neville, love, buddy, I love you, but you need to get your head examined. Memory loss at this age isn't normal."