Neville, his face tear-streaked, clutching his wrist, hobbled off with Madam Hooch, who had her arm around him. No sooner were they out of earshot than Malfoy burst into laughter .
A wafer of a moon was shining over Gatsby's house, making the night fine as before and surviving the laughter and the sound of his still glowing garden.
They are noting that the Victorians suddenly seem to become more human as the hundred-or-so years that separate us fade away through our common experience of laughter.