"You haven't come to see me in one hundred and fifty-three days."
As Snape ignored the "Out of Order" sign and pushed open the door to the girls' bathroom on the second floor, Moaning Myrtle unexpectedly floated out from behind a faucet.
Her pearly glasses were misted with water as she blocked the doorway, saying mournfully, "You said you'd come see me... I've been waiting for you here..."
"Myrtle!" Snape was startled by her sudden appearance and took a half-step back. "I'm here now, aren't I!"
As he spoke, he quickly squeezed into the bathroom and swiftly pulled the door shut to avoid being seen by passing students entering the girls' lavatory.
As Snape passed through Myrtle's body, he suddenly felt as if he'd jumped into a bucket of ice water, causing him to shiver uncontrollably, his teeth chattering slightly.
"Not only that," Snape brought his hands to his mouth and blew a few warm breaths, "do you want to move to a different place? Somewhere better than here. I also have new friends I'd like to introduce you to."
"A new place?" A glimmer of hope flashed in Myrtle's eyes, but it quickly faded, and her expression became somewhat crestfallen. "I don't want to be laughed at or driven away again."
"That place is quite hidden, trust me," Snape said gently. "Do you want to come and see it with me? If it's not suitable, you can always come back."
Myrtle hesitated, then nodded slightly. "Okay, I'm willing to go and see."
Snape told Myrtle their destination, but to his surprise, Myrtle simply floated through the bathroom ceiling.
"I'll wait for you up there, Severus."
Snape hurried, running through the winding corridors towards the painting of the trolls dancing ballet on the eighth floor.
By the time he arrived, it seemed Myrtle had been waiting for a while. She was floating in the air, her body gently rising and falling.
"No one saw you, did they?" Snape asked.
"No," Myrtle said. "There's no one around here at all."
"Good," Snape said, steadying his breath, and pointed to the seemingly ordinary stone wall in front of them. "Myrtle, would you mind going through this plain wall and seeing what's inside?"
Myrtle looked at him quizzically but didn't ask any further questions, obediently phasing into the stone wall where the Room of Requirement's entrance was located.
A few seconds later, she floated out again, looking utterly confused. "There's nothing inside, just rock."
"Thank you, Myrtle." Snape nodded in satisfaction. "That means not only people, but ghosts are also unable to directly enter that place."
"What place?" Myrtle was even more bewildered. "Is there something in here?"
"Just a moment, you'll find out soon."
After Snape finished speaking, he approached the stone wall and knocked on it three times with his knuckles. Then he slowly clapped his hands together three times, followed by three quick knocks on the wall.
Suddenly, an ancient oak door appeared on the plain wall.
With a creak, the door opened, and Pandora poked her head out. "Come in quickly."
Snape squeezed in sideways, then quickly poked his head back out to wave Myrtle in. "Come in quickly."
After Myrtle floated inside, he swiftly pulled the door shut.
"First guess was right," Snape said happily to Pandora. "When someone is in the Room of Requirement, even ghosts can't get in."
"Oh, by the way," he turned to Myrtle and asked, "do you know Pandora?"
"Yes," Myrtle said, flying a circle around Pandora, speaking softly, "a girl who's also laughed at, just like me..."
"This is a good place for us, isn't it?" Myrtle said excitedly. "A place Peeves definitely can't get into..."
"I think he can't get in, Myrtle," Snape said. "Later, I'll need your help testing other things."
Myrtle joyfully did a somersault, her eyes gleaming with anticipation. "Will I live here from now on?"
"I think so." Snape looked at Pandora, who also smiled and nodded at Myrtle, indicating her agreement.
"Is there anything I can do for you?" Myrtle bowed properly, then let out a cheerful giggle.
"The rule of this place is that as long as there's one person inside," Snape explained, "people outside cannot open the door."
"Now, we also want to know if the same applies if a ghost is inside the room."
"This means," Myrtle pushed up her glasses, a gleam flashing on the pearly lenses, "that next, you two go out and leave me in the room."
"Clever," Snape said approvingly. "But first, you should see if you can pass through the walls of this room indoors."
Myrtle immediately phased into the stone wall of the Room of Requirement.
After a short while, she floated out, shaking her head. "No, it's the same as outside, endless walls."
"Alright," Snape said, placing a hook on the doorknob. The other end of the hook was connected to a strange device. "This device can pull the door open when it hears a loud sound."
"Do you remember the pattern of knocking and clapping I used outside the door just now?" he asked Myrtle. "Three short, three long, then three short again. You can only open the door when you hear this sound, how about that?"
Snape demonstrated the knocking pattern to Myrtle two more times, then leaned by the door to listen for any sounds outside before nodding to Myrtle.
Myrtle took a deep breath and let out a deafening scream.
"Stop!" Snape quickly stopped her from screaming further. By now, the door had been pulled ajar by Pandora's magical device, which was primarily made from an Erkling's vocal cords. "No need to scream once the door is open!"
Then, he and Pandora left the Room of Requirement, watching the entrance disappear into the wall again.
After failing to open the Room of Requirement using conventional methods, Pandora cast a Muffliato Charm on the adjacent corridors, then created the sound according to the pattern.
The door opened, and they went inside again.
"Fantastic!" Snape and Pandora enthusiastically high-fived, their faces beaming with joy. "This place will be much safer for us now! Myrtle, if you want to go out and wander around, just say so in advance."
"Go out? No," Myrtle said. "I like this sunny place, as long as you two visit often."
Then, she let out a giggle. "What a strange group of people: Moaning Myrtle, crazy Pandora, and Severus, who likes to watch naked people..."
"Hey!" Snape couldn't help but exclaim. "Weren't you always in the bathroom?"
"Sometimes I sneak out," Myrtle said with a sly smile. "I've seen yours too..."