"I still think that it was a flying saucer that we saw last night," Harry insisted.
Hermione shook her head. "There has to be some rational explanation. A dragon, or a mischievous broomstick-rider using illuminating spells, or even a weather balloon."
"I might have known you'd try to Scully it," said Harry.
"To what?" Ron turned to join in the conversation. "Is that a spell that I haven't heard of?"
"It's a Muggle thing," Harry said. "Don't worry about it, Ron."
"Flying saucers are Muggle things?"
Harry sighed. He opened his mouth to explain but was interrupted by the arrival of a rather flustered Ginny.
"Hey, there's something really strange going on," she announced as she joined the group.
"Stranger than flying saucers?" Harry's eyebrows climbed.
"It's the house elves," Ginny explained. "They're acting very oddly. And one of them called me 'Earthling'."
Harry's eyebrows rose higher than the frames of his glasses. "Earthling? How weird. Perhaps we should talk to Dobby."
"I can't find Dobby," Ginny said. "I thought I heard his voice calling out 'Watch the skies! You're next!' I looked everywhere for him but all I found was… this." She held up a strange green object, rather like a seed pod, which was about the size of a house elf. It was hollow and empty. "Any idea what it is?"
Harry peered at it. "Oh dear," he said. "I have a horrible feeling that I know what we're up against. It's the Invasion of the Dobby Snatchers."