Ron quite liked the idea of using the Summoning Charm again—Harry had explained about Aqua-Lungs, and Ron couldn’t see why Harry shouldn’t Summon one from the nearest Muggle town. Hermione squashed this plan by pointing out that, in the unlikely event that Harry managed to learn how to operate an Aqua-Lung within the set limit of an hour, he was sure to be disqualified for breaking the International Code of Wizarding Secrecy—it was too much to hope that no Muggles would spot an Aqua-Lung zooming across the countryside to Hogwarts.

“Of course, the ideal solution would be for you to Transfigure yourself into a submarine or something,” Hermione said. “If only we’d done human Transfiguration already! But I don’t think we start that until sixth year, and it can go badly wrong if you don’t know what you’re doing . . . ”

“Yeah, I don’t fancy walking around with a periscope sticking out of my head,” said Harry. “I s’pose I could always attack someone in front of Moody; he might do it for me . . . ”

“I don’t think he’d let you choose what you wanted to be turned into, though,” said Hermione seriously. “No, I think your best chance is some sort of charm.”

So Harry, thinking that he would soon have had enough of the library to last him a lifetime, buried himself once more among the dusty volumes, looking for any spell that might enable a human to survive without oxygen. However, though he, Ron, and Hermione searched through their lunchtimes, evenings, and whole weekends—though Harry asked Professor McGonagall for a note of permission to use the Restricted Section, and even asked the irritable, vulture-like librarian, Madam Pince, for help—they found nothing whatsoever that would enable Harry to spend an hour underwater and live to tell the tale.

Familiar flutterings of panic were starting to disturb Harry now, and he was finding it difficult to concentrate in class again. The lake, which Harry had always taken for granted as just another feature of the grounds, drew his eyes whenever he was near a classroom window, a great, iron-gray mass of chilly water, whose dark and icy depths were starting to seem as distant as the moon.

Just as it had before he faced the Horntail, time was slipping away as though somebody had bewitched the clocks to go extra-fast. There was a week to go before February the twenty-fourth (there was still time) . . . there were five days to go (he was bound to find something soon) . . . three days to go (please let me find something . . . please) . . .

With two days left, Harry started to go off food again. The only good thing about breakfast on Monday was the return of the brown owl he had sent to Sirius. He pulled off the parchment, unrolled it, and saw the shortest letter Sirius had ever written to him.

Send date of next Hogsmeade weekend by return owl.