"Okay," said Harry, after he'd been shoved inside a broom closet once they'd arrived three hours into the past. "What's the plan?"
"Well," said Hermione thoughtfully, "Professor Dumbledore specifically mentioned the thirteenth window from the right of the West Tower, which means we're meant to rescue Sirius by flying him out."
"We could use my Nimbus 2000," offered Harry.
"It's no use," answered Hermione. "Broomstick enchantments won't work near the castle while it's on high alert against invasions. Unless…"
Harry and Hermione both looked at Daphne, who shifted uncomfortably from being stared at. Hadn't they seen Oleandra fly in the Shrieking Shack after she'd been shot outside through a few walls on the second floor?
"What are you looking at me like that for?" said Daphne coolly. "I don't know how to fly. Flying is my sister's thing. What, you think just because we're twins, we're exactly the same?"
"Well, the Weasley twins are like that," said Harry. "Oh, wait, I got it. Professor Dumbledore also said we'd be able to save more than one innocent life if all went well. He didn't just mean Lupin and Sirius, I think he also meant Buckbeak."
"Of course!" Hermione realized. "That's why he said three hours!" Hermione switched to whispering. "Shh! Listen! Someone's coming! I think— I think it might be us!"
Daphne tried looking through the keyhole, but she didn't see anyone. And then she remembered Harry's floating head; he owned an Invisibility Cloak, of course they'd use it to sneak out!
"Yes," confirmed Hermione. "Slow steps, no more than three sets of footsteps. That's us; we're going slowly because we're all under the Cloak!"
"Where did you get that hourglass thing?" asked Harry, pointing towards Daphne's neck.
"It's a Time-Turner," explained Hermione in a low voice. "We got it from Professor McGonagall on our first day of school. We've been using it all year to get to all of our classes."
"I wanted one of my own," whispered Daphne, "but apparently it was too dangerous allowing students of the same year to run around with their own separate Time-Turners, in case they ran into each other and created paradoxes."
"So, we were made to share," completed Hermione. "I would have told you and Ron about it, but were made not to tell anyone. Professor McGonagall and Professor Snape had to write all sorts of letters to the Ministry so that we could have one between the two of us. There are loads of rules, too. We're only supposed to use it for our studies, and we can only go back five hours."
"So, Dumbledore asked us to go back three hours so that we can save Hagrid's Hippogriff," said Daphne thoughtfully, "which we can use to fly up to Black's tower and free him. Does that sound about right?"
"Three hours ago, which is now, we were just heading to Hagrid's," said Harry. "Which is why our past selves just passed in front of us, invisible."
"Good thing we have your Invisibility Cloak," said Hermione, "or it would have been next to impossible to do all that without being seen."
"About that…" said Harry hesitantly. "I left the Cloak at the Whomping Willow. I don't have it right now; we'll have to grab it from where I left it after our past selves go after Ron."
"Enough," said Daphne. "We'll have to make do without it; we're wasting time."
Harry pressed his ear against the door. Having determined that nobody was on the other side, the three made a run for it. They darted out of the Entrance Hall and down the stone steps, and across the small bridge. Once there, they leaned against a castle wall. They were right under the Divination Classroom, Daphne realized.
"We can't stay here," said Hermione, who was looking terrified at the prospect of being erased from history.
"We won't," Harry reassured her. "We'll continue along this wall, go around the Greenhouse and the Whomping Willow, and straight into the Forbidden Forest."
"Good idea," said Hermione. "That way, our past selves won't accidentally see us on the way."
The three of them once again started running, following the path that Harry had described. Once they were in the Forbidden Forest, they could finally relax a little. From there, they only needed to walk along the edge of the forest, taking care to remain out of sight behind the trees until they reached Hagrid's cabin.
"It's us. We're wearing the Invisibility Cloak. Let us in and we can take it off," said a disembodied voice.
"That was your voice," said Daphne to Harry. "The moment Hagrid closes the door, your past selves won't be able to see you. There! Let's get this over with; we grab Buckbeak and we drag it into the forest!"
"No," whispered Hermione. "It's too soon! We need the Committee people to see that Buckbeak's still there; otherwise, they'll think Hagrid set it free, and he'll get in trouble! We need to wait!"
"We'll have about sixty seconds," said Harry. "That's not much time."
"What was that?" hissed Daphne in a low voice. "I think something just broke!"
"That's normal," whispered Hermione, "Hagrid dropped a jug; which means that moments later, I'll find Scabbers—"
"You know," said Harry, who was thinking out loud, "we still don't know for sure if Scabbers is actually Pettigrew. What if we just ran in there and grabbed him?"
"NO!" cried Hermione, before lowering her voice immediately afterwards, "Don't you understand? Once something's happened, it's set in stone! You can't ever change it! Do you remember seeing us bursting into Hagrid's cabin and tearing Scabbers out of Ron's hands? How do you think you'd have reacted if you'd seen another one of you doing exactly that?"
"I'd think I'd gone mad," answered Harry, "or I'd think there was some Dark Magic going on— Hang on, Hermione; aren't we changing the past by rescuing Buckbeak?"
"Did you actually see Buckbeak being executed?" asked Daphne. "With your own eyes?"
"We saw the axe—" Harry began, "wait, we never actually did see it happen, did we?"
"Then you're fine," said Daphne. "As long as you didn't verify the outcome for yourself, it's still up in the air until you do, even if it's already happened from your temporal perspective."
"There!" said Hermione, pointing towards the castle. "They're coming! Which means we're about to leave through the hut's back door!"