The first time Neville could no longer deny something was up with Malfoy was when he happened upon Macmillan tagging FREE HOGWARTS all over a set of moving stairs in bright yellow Muggle paint. The Slytherin Head Boy had arrived first yet was not doing anything, was just standing stock still at the bottom of the stairs, staring at the spectacle. It was possible that he was speechless in face of the Hufflepuff’s gall, and for a moment Neville considered the possibility that Ernie might have Stupefied him, but he could see his fingers twitching, could see his chest rise and fall as he was breathing.
If he’d been asked about such a scenario beforehand, Neville would have said the Slytherin would have already have dragged the other boy off for punishment, getting a few good hexes in himself before delivering the culprit to his favourite Muggle Studies Professor for some proper cursing. It had not been that long ago that Neville had seen Malfoy and Parkinson do the same thing to Terry Boot. Right now, however, Malfoy was just watching. It was possible that he was only trying to figure out the best hex to use, but necessity had taught Neville quite a bit about spotting ill intent, and it it did not fit with the impression he was getting.
The only sounds were the hiss of the spray paint and the stairs creaking as they moved. Even the portraits around the hallway were silent, watching avidly.
For a moment, Neville debated whether or not to stun Malfoy himself, or at least call out to Ernie in warning. However, while the outcome of this situation was still uncertain, Stupefying Malfoy definitely would result in retaliation. Announcing his presence, too, would force Malfoy into action. Neville doubted the Head Boy would let himself be lenient while aware of another’s observation. He was curious what Malfoy would do now that there were no Slytherins around, now that he believed himself alone.
The moment was broken by the sound of approaching feet. All three students’ heads jerked up in anxious recognition; recognizing the Professors by their footsteps had become a survival trait even for the Slytherins. Ernie was staring downwards at the paint in his hand, white-faced. The stairway he had been working on was hanging in midair and had paused like the rest of them, he was trapped, the only escape being down. Being caught in flagranti the punishment would be so much worse than if Carrow had simply heard of the misdeed second-hand.
The portraits’ inhabitants all ducked below their frames as the steps drew near. Neville braced himself for an intervention he knew was going to be an unhealthy life choice when Malfoy suddenly made a move and cut off the Professor’s path.
“Professor Carrow,” he said in that charming tone of voice he had adopted during class and that always seemed to get him the closest thing Alecto Carrow could come to a delighted smile. “Professor, I am so glad to run into you. Millicent has just told me the most outrageous thing, and I would have hated to wait until tomorrow for an opportunity to ask you if she was exaggerating. Is it true that sharing the same meal with a Mudblood can cause a Pureblood to have a, shall we say, unfortunate reaction? If so, I demand that Professor Slughorn prepare a remedial potion at once to make up for the years we had to spend close to these awful creatures. I will not take no for an answer.”
Ernie’s eyes were bugging out of his face as Draco casually blocked the Professor’s view of the stairs. “Dear boy,” she exclaimed, faking shock and feeling scandalized and delighted at being approached about her field outside the classroom. “It’s rare that the Mudblood contamination has consequences as dire as you imply, but unfortunately it has been known to happen. Your dear friend is right to be concerned, after all, the traitors had wormed their way even into Slytherin. Come, help me search for a text you all should be reading...”
Their voices faded, and the two DA members waited for a few moments before Ernie hastily finished off the ‘S’ and took off at a run. Neville followed at a much more sedate pace, deeply in thought about what he had just seen.