"Haven't you two finished that yet?" Hermione asked, exasperated, as Harry added another card to their intricate Exploding Snap house of cards design. He was vaguely worried about the sunlight streaming in through the common room window - would the heat shorten the life span of the deck of cards? - but was nonetheless engrossed in completing the design before it exploded.
"But we've finished our studying, Hermione!" Ron protested, then quailed under her disapproving stare. "Mostly. I swear, I've just got this one last thing for Trelawney, but it'll be a snap and - "
"Somebody has a guilty conscience," Hermione responded loftily. "I wasn't even talking about that. I've just been thinking ..." Her pause was made far more dramatic by the sudden explosion of Harry and Ron's house of cards, which singed their eyebrows and darkened Harry's glasses. He took them off hastily, tapping them with his wand and muttering "Scourgify" under his breath.
"I didn't want to do it at first, I thought it was way too dangerous, but I've been looking up past uses of the spell in the Restricted Section - oh, what? Professor Vector gave me a pass for another essay - and it sounds like loads of fun - "
"Oh, out with it already!" Ron snapped. He had considerably perked up at the word "fun." Anything Herrmione thought to be fun was either extraordinarily so, or the exact opposite, and either was worth listening to, just to be on the safe side.
"I think we should try using Defodio to clear the collapsed tunnel to Hogsmeade that's on Harry's map," Hermione blurted out, then turned a deep red. Harry raised his eyebrows. Ron choked on his own spit, and had to be hit in the back a few times by Harry.
"Cheers, Harry. And you - " Hermione cringed - "what the hell have you done with Hermione?" Hermione cleared her throat, still not quite meeting their eyes.
"It's just a pity, how long we have to wait until the next Hogsmeade trip, that's all," she said quickly. "It's a beautiful day and I don't want to waste it here, since all I've done for weeks is study. Midterms are over and we deserve to celebrate."
"But - "
"Sounds fair enough to me," Harry said firmly, over Ron's protests, and aiming a kick at him under the table. It was rather effective. He didn't want to risk Hermione changing her mind, and he knew they couldn't do it without her help, or at least, not in decent time. Why question her motives when she was willing to help them escape the grounds for the afternoon? He was running low on sugar quills, anyway, and he wanted to swing by Zonko's - no, he corrected himself; the Hogsmeade branch of Weasleys' Wizard Wheezes - to see what new things George had imagined up lately.
"Well then, what are you two waiting for?" Hermione said briskly, already heading for the exit. Harry and Ron looked at each other momentarily, then scrambled after their best friend, out of the portrait hole. They didn't need the Marauder's Map; Harry remembered exactly where that exit was.
"Why couldn't you have found a spell like this a few years ago?" Ron asked her, panting to keep up. Although Hermione was shorter, she could definitely set the pace when she had something up her sleeve. Nobody quite wanted to say it out loud, but they were all wishing that Fred and George were still here - alive and in one piece, respectively - to come along. Fred would have been proud. Down five staircases - it would have been three, but one of them decided to change direction while the trio was coming down it - and quietly past Peeves, who was quite busy strewing wool across the Owlery floor ... finally Hermione slowed down, just before the statue of Garutio the Garish. Ron looked around, puzzled, and Harry followed suit. There wasn't anything here but an old doorway, which everyone above first year knew was just a solid wall, pretending.
"Er, Hermione - " Harry began, but she shushed him impatiently. "It isn't just pretending," she said, looking excited. "I overheard Flitwick and Filch talking about it. Apparently it's a door that's pretending to be a solid wall, and that solid wall is pretending to be a door!"