against Ravenclaw? I can't afford to fall off again. If we lose this game we've lost the Quidditch Cup!" 

"All right then... " said Lupin. "You might want to select 'other memory, a happy memory, I mean, to concentrate on.... That one doesn't seem to have been strong enough...." 

Harry thought hard and decided his feelings when Gryffindor had won the House Championship last year had definitely qualified as very happy. He gripped his wand tightly again and took up his position in the middle of the classroom. 

"Ready?" said Lupin, gripping the box lid.

 "Ready," said Harry; trying hard to fill his head with happy thoughts about Gryffindor winning, and not dark thoughts about what was going to happen when the box opened.

 "Go!" said Lupin, pulling off the lid. The room went icily cold and dark once more. The dementor glided forward, drawing its breath; one rotting hand was extending toward Harry -

 "Expecto patronum!" Harry yelled. "Expecto patronum! Expecto Pat --" 

White fog obscured his senses... big, blurred shapes were moving around him... then came a new voice, a man's voice, shouting, panicking -- 

"Lily, take them and go! It's him! Go! Run! I'll hold him off --" 

The sounds of someone stumbling ftom a room -- a door bursting open -- a cackle of high- pitched laughter -- 

"Harry! Harry... wake up...." 

Lupin was tapping Harry hard on the face. This time it was a minute before Harry understood why he was lying on a dusty classroom floor. 

"I should have brought my bike helmet. I'm going to get a concussion." Amelia murmured.

"I heard my dad," Harry mumbled. "That's the first time I've ever heard him -- he tried to take on Voldemort himself, to give my mum time to run for it...."