As Harry had no idea how long a bath he would need to work out the secret of the golden egg, he decided to do it at night, when he would be able to take as much time as he wanted. Reluctant though he was to accept more favors from Cedric, he also decided to use the prefects’ bathroom; far fewer people were allowed in there, so it was much less likely that he would be disturbed.

Harry planned his excursion carefully, because he had been caught out of bed and out-of-bounds by Filch the caretaker in the middle of the night once before, and had no desire to repeat the experience. The Invisibility Cloak would, of course, be essential, and as an added precaution, Harry thought he would take the Marauder’s Map, which, next to the cloak, was the most useful aid to rule-breaking Harry owned. The map showed the whole of Hogwarts, including its many shortcuts and secret passageways and, most important of all, it revealed the people inside the castle as minuscule, labeled dots, moving around the corridors, so that Harry would be forewarned if somebody was approaching the bathroom.

On Thursday night, Harry sneaked up to bed, put on the cloak, crept back downstairs, and, just as he had done on the night when Hagrid had shown him the dragons, waited for the portrait hole to open. This time it was Ron who waited outside to give the Fat Lady the password (“banana fritters”). “Good luck,” Ron muttered, climbing into the room as Harry crept out past him.

It was awkward moving under the cloak tonight, because Harry had the heavy egg under one arm and the map held in front of his nose with the other. However, the moonlit corridors were empty and silent, and by checking the map at strategic intervals, Harry was able to ensure that he wouldn’t run into anyone he wanted to avoid. When he reached the statue of Boris the Bewildered, a lost-looking wizard with his gloves on the wrong hands, he located the right door, leaned close to it, and muttered the password, “Pine fresh,” just as Cedric had told him.

The door creaked open. Harry slipped inside, bolted the door behind him, and pulled off the Invisibility Cloak, looking around.