"Have you checked the painting?" Professor Sicarius' voice questioned. Rose suddenly found herself with the almost irresistible urge to sneeze, and stuffed her fist under her nose in an attempt to quell the sensation. She couldn't give them away now - Sicarius would almost certainly kill them on the spot, and besides, they were so close to figuring out the case!
Suddenly, she remembered a spell that her dad had taught Hugo before he'd started in his first year at Hogwarts. It was supposed to allow you to talk in class by filling surrounding people's ears with a gentle buzzing sound, but Rose hadn't ever needed or wanted to use it, unlike her not quite so studious brother.
"Muffliato!" She jabbed her wand towards the cupboard doors again.
"What are you doing?" Scorpius whispered.
"Just a second," Rose prayed that the spell had worked, and finally gave in to the impulse to sneeze. After a few tense seconds, she realised that the Professor had not in fact heard her, and grinned at Scorpius.
"They won't be able to hear us now," she motioned in the direction of the voices. "Let's get a bit more comfortable," she suggested, and manoeuvred herself around so that she was facing Scorpius, who smirked and slid down to the floor. Rose followed suit so that they were sitting on the bottom of the cupboard, resting against opposing sides.
"I checked the painting for any traces of magic but nothing came up except a few hints of the old animation spell," the higher voice wafted into the cupboard, and Rose gave a small smile of satisfaction - she'd been right.
"Do you know what this means, Fawley?" Sicarius paced back and forth, edging closer to the cupboard that Rpse and Scorpius were sitting in, and Rose's heart started pounding. What if he'd realised that they were there? But the professor stopped and sat down somewhere over the other side of the room.
"No, sir," the man called Fawley quavered.
"It means," Sicarius paused, "that the painting - and the bill - is still in the castle." The office was silent until the other man coughed nervously.
"But Sicarius, sir, how do we know that Leach definitely put the papers in a portrait? Couldn't he have hidden it elsewhere - "
"No," the Potions Master's voice echoed around the room. "Our people checked his wand after they finally caught up with him, and the last spell it cast was evidently one to transport objects into a magical painting," Sicarius stated confidently, as if he'd repeated those exact words many times. "The Minister came to Hogwarts, put the bill into a painting, and then took the portrait of Scamander to hide in the Ministry, which is where we found him. There was no time for him to take any other paintings out of the school, so the papers must still be here, somewhere."
There was a pause again.
"Then what do you suggest we do then, sir?" Fawley ventured. There was a sound of rustling robes, and Rose assumed that the professor had gotten out of his chair.
"Send me a group of ten to twelve through the floo network into my office. I'll cause a distraction so all students and teachers are contained, and then we can begin the search," Sicarius ordered.
"Yes, sir, on it sir," the other man mumbled.
"Now go - I must get the diversion in order." There was a whoosh of air and the office fell silent. The professor whisked himself out of the room, but Rose and Scorpius waited for a few more minutes until they were sure he was gone. They clambered out of the cupboard and looked around the office.
"We'd better go meet the others," Scorpius said finally. "We don't want to be caught in here when Sicarius' reinforcements come in."
They rushed out of the Potion Master's office, but Rose was pondering what they'd just heard.
"If you were Nobby Leach," she said to Scorpius thoughtfully, "which painting would you choose to hide the documents you'd risked your life for?" He frowned and bit his lip, then pulled Rose around the corner and stopped her from flying into a suit of armour.
"I'd keep the papers with a painting who I knew I could trust," he started. "A portrait who would protect the bill with his or her life, who was brave and resourceful, but - ah! - a painting which no one would expect me to choose." They began climbing the staircases up to the seventh floor. "Someone who seemed crazy or ditzy, just not a good choice in general, but who was actually loyal and completely faithful." Scorpius kept them going faster as the words rolled off his tongue.
"Someone who I was familiar with but who no one else really gave a second thought to," he turned and gave Rose a wry grin. "What I'm really saying is that I'd give it to the underdog." They were on the second floor now, and a staircase swung forward to meet them as they continued to clamber upwards. "Know any paintings like that?"
Rose thought back to that long list that she'd made a few months ago now. After going through it so many times, both for looking for a portrait to test her spell for Fawkes on, and for finding Newt's painting, she probably knew at least half of the paintings in the castle - though it was likely to be even more. Who was brave, loyal and trustworthy? A portrait would usually only have the most basic attributes of the person it represented - so it was most likely to be a Gryffindor or Hufflepuff.
Someone who was eccentric or seemingly simple, someone who people laughed at or just ignored. A painting which called out to students in the hallways, who was conspicuous yet hid in plain sight, who no one would ever think of entrusting anyone to ...
"No," Rose breathed. "Was that a 'no, you don't know any paintings'?" Scorpius puffed.
"I - I've got an idea, but it's crazy," she looked around to see that they'd reached the sixth floor and were halfway up the staircase to the seventh.
"I like crazy," Scorpius grinned, and Rose shook her head at him. "So?" He prompted her.
"I think - " she broke off as they stopped at the top of the stairs.
Before them was the seventh floor, and just down the corridor was the tapestry behind which Rose prayed the rest of the reformed DA was waiting. They were going to need help if they were to face a dozen highly trained wizards who were probably not above using Unforgivable Curses. She pulled Scorpius over to the entrance to the secret passage.
"I think we need to pay Sir Cadogan a visit," she finished, and pushed the tapestry which depicted Barnabus the Barmy failing to teach trolls ballet aside.