"Oh! Right! Things were different now..." He seemed to think of something amusing and grinned. "Now he could only gnaw on grapefruit while watching TV!"
"Water vapor... If that was the case..." Vizet murmured, then looked at Harry and asked, "Harry, do you know about these things?"
"For example, if you put a straw into a glass full of water, the straw looks different, as if it suddenly bent... and the bottom of a swimming pool is deeper than it looks..."
"I do!" Harry nodded. He scratched his head and said, "But I can't really explain why. It seems to have something to do with some scientific principle..."
Vizet went on asking, "From Dudley's reading materials, do you know how a 'mirage' forms?"
"Uh..." Harry said, a little embarrassed, "I forgot... I can't really remember. It seemed to be something about... something to do with light..."
"It's all right!" Vizet waved a hand. "I'll teach you a spell..."
"Now?" Harry froze for a moment, then asked in puzzlement, "Right here?"
"Yes!" Vizet nodded. "I think this spell might not be that difficult for you. It's a kind of Weather Charm, and it's called the 'Mirage Charm'..."
"Oh!" Harry seemed to think of something. "I know about this spell called the 'Mirage Charm'!"
"Sirius Black told me before that the 'Image Projection Screen' actually used this spell!"