The five words you don't want to hear when you've spent 14 hours studying yesterday, sure you were forgetting something. You did your Arithmancy, an extra foot on History of Magic essay, and studied for exams in Muggle Studies, Divination, and Potions, plus two hours preparing Buckbeak's appeal. She knew something was missing. She was forgetting something. Hermione had supposed that it was the Time-Turner, playing with time had unknown side effects. She resolved to do it during the 25th hour of the 32nd day of this month. It wasn't like she couldn't do it. It was Professor McGonagall who said those words, and Hermione knew before she had even finished the third word. She had failed.
"Please take out your homework." Now that Hermione remembered, there had been homework, an essay on transformation on guinea pigs. Professor McGonagall went from desk to desk, picking up essays from each desk. When she saw no homework on Hermione's desk, she passes by wordlessly. Hermione looked down, pretending to examine the fur color of her guinea pig. Ron snorted, but Hermione pretended she didn't notice. After all the essays were collected, class continued as usual. But Hermione couldn't concentrate. She had forgotten a very important homework assignment, and even though she had learned this a year ago, she just couldn't get it right. She started to stare at the guinea pig and then she just…skipped. Everyone was in positions that they weren't before. Time was breaking down, just a little bit, but it was all the same. She couldn't keep doing this.
Finally, Transformation finished, and Hermione stood up quickly, banging her knee on the desk. Everyone filed out of the classroom, Hermione last. But Professor McGonagall stopped her. "Miss Granger, can you please stay after class?" Hermione turned around. This would be the part where McGonagall would say how disappointed she was with Hermione, making her feel even worse. And she knew she deserved it too. She had a Time-Turner, it wasn't as if she didn't have the time.
"Miss Granger," she began. Just get it over with already, Hermione thought. "I'm very worried about you." That wasn't what Hermione had been expecting at all. "You're working yourself too hard. Even if you can't see the effects, I certainly can. As can Professor Dumbledore."
Hermione thought it unlikely that Dumbledore actually payed attention to her, or anyone for that matter, but she didn't say anything on that matter. "When I gave you the Time-Turner, the Ministry cautioned me on what can happen if you over-use it. I just want you to understand that you can turn it in at any time and drop the necessary classes." Professor McGonagall told her. She seemed to be waiting for Hermione to say something.
"Professor, I really need to take those classes."
"You'll soon come to realize that you really don't. I just ask you to think about your health."
"I will."
"You may go now." Professor McGonagall told her.
"And Miss Granger," she added as Hermione turned to leave, "that was the most excellent transfiguration of a guinea pig I've seen."