"Your Fwooper." Pomona placed the birdcage on Snape's desk.
Perhaps it sensed something; it fluttered about the cage in panic. Unfortunately, the cage was sturdy, and it could not escape.
"Do you feel sorry for it?" Snape asked.
If it had been for Veritaserum or a memory potion, a feather would have been enough. But he wanted the entire bird alive, which meant he wanted the Fwooper's final cry at the moment of its death.
"I shouldn't have told you that fairy tale about the mermaid," Pomona said sorrowfully.
"I don't think a bedtime story would be enough to influence me," he said coldly. "I'm conducting an experiment involving time travel."
"What?" Pomona was utterly astonished. "What does this have to do with time travel?"
"Have you heard Muggle music?" Severus asked.
Pomona nodded.
"My father once had a portable cassette recorder. It could play two tapes, switching between them. They each had their own controls and could be rewound before being played."
Pomona recalled that it had been back in the seventies. On the streets, disco youths were everywhere, wearing bell-bottoms, sporting fluffy perms and sunglasses, carrying bulky cassette players. They would deliberately turn their music up loud.
Then Severus took out a Golden Egg. He twisted the three-toed bird's foot at the top, and the egg opened, revealing a glass chamber inside. It was still empty for now, but potion could be poured into it later.
"On land, it will continuously play tape A. In water, it will continuously play tape B. This bird spends most of its time in a cage, listening to bird calls. I think people would rather listen to a mermaid's song than birdsong—unless they also wish to prove that an Augurey's song will not drive people mad." Severus pressed the switch again and