He made sure Myrtle had her glasses well covered before hoisting himself out of the bath, wrapping the towel firmly around his waist, and going to retrieve the egg. Once he was back in the water, Myrtle peered through her fingers and said, “Go on, then . . . open it under the water!”

Harry lowered the egg beneath the foamy surface and opened it . . . and this time, it did not wail. A gurgling song was coming out of it, a song whose words he couldn’t distinguish through the water.

“You need to put your head under too,” said Myrtle, who seemed to be thoroughly enjoying bossing him around. “Go on!”

Harry took a great breath and slid under the surface—and now, sitting on the marble bottom of the bubble-filled bath, he heard a chorus of eerie voices singing to him from the open egg in his hands:

“Come seek us where our voices sound,

We cannot sing above the ground,

And while you’re searching ponder this:

We’ve taken what you’ll sorely miss,

An hour long you’ll have to look,

And to recover what we took,

But past an hour—the prospect’s black,

Too late, it’s gone, it won’t come back.”

Harry let himself float back upward and broke the bubbly surface, shaking his hair out of his eyes.

“Hear it?” said Myrtle.

“Yeah . . . ‘Come seek us where our voices sound . . . ’ and if I need persuading . . . hang on, I need to listen again . . . ”

He sank back beneath the water. It took three more underwater renditions of the egg’s song before Harry had it memorized; then he trod water for a while, thinking hard, while Myrtle sat and watched him.

“I’ve got to go and look for people who can’t use their voices above the ground . . . ” he said slowly. “Er . . . who could that be?”

“Slow, aren’t you?”

He had never seen Moaning Myrtle so cheerful, apart from the day when a dose of Polyjuice Potion had given Hermione the hairy face and tail of a cat. Harry stared around the bathroom, thinking . . . if the voices could only be heard underwater, then it made sense for them to belong to underwater creatures. He ran this theory past Myrtle, who smirked at him.

“Well, that’s what Diggory thought,” she said. “He lay there talking to himself for ages about it. Ages and ages . . . nearly all the bubbles had gone . . . ”

“Underwater . . . ” Harry said slowly. “Myrtle . . . what lives in the lake, apart from the giant squid?”

“Oh all sorts,” she said. “I sometimes go down there . . . sometimes don’t have any choice, if someone flushes my toilet when I’m not expecting it . . . ”

Trying not to think about Moaning Myrtle zooming down a pipe to the lake with the contents of a toilet, Harry said, “Well, does anything in there have a human voice? Hang on—”

Harry’s eyes had fallen on the picture of the snoozing mermaid on the wall.