For the space of three, maybe four heartbeats, Severus was almost sure the Brat Who Confounded Him would protest, or refuse to follow the very simple order to leave, but then Potter nodded, said, "Yes, sir," and escaped the office without looking back.
Severus sighed and went back to his grading.
The next morning's classes were under constant interruption by the unfettered poltergeist, so much so that Dumbledore himself had to step in at least once, when Peeves' antics caused an entire roomful of second year Gryffindors to start hexing each other in an effort to get rid of him, right through the robes he had jerked over all of their heads.
At lunch, Severus kindly hid his smirk over the incident from Minerva, as she was none too pleased about the resulting flurry of feathers and thistle down in her classroom, and had spent more than enough time cleaning up after her class.
An extra special surprise was that Professor Quirrell had canceled all his classes for the day, claiming a bout of flu. Having all the Defense students running about in the halls when everyone else was in class was just this short of the best fun Severus had ever borne witness to on a Monday.
But all that aggravation went out of his head completely when, on the way back to his office before his first afternoon class, Severus at last found the Bloody Baron.
The ghost was hovering just in front of his office door, in fact. He looked . . . less substantial than usual, for the Bloody Baron, though the silver streaks of his blood were brighter than ever.
Severus stepped closer, but stayed slightly out of range of touch. If the Baron had turned . . . well, evil, Severus would not present him with an easy target, at least. He did, however, erect a simple privacy ward, so anything spoken here now would remain between only the two of them.
"Severus Snape," the ghost intoned as it turned to see him. His voice was breathy, almost a whisper, and curiously flat. His eyes were odd, too, dark tunnels with a touch of madness.
"Baron." Severus inclined his head slightly, but did not lower his gaze. "We've been looking for you."
"The boy . . . is he well?"
"By boy, I presume you mean the Potter child." The Bloody Baron nodded, barely, and Severus said, "He fares well enough now. But he lost blood, a lot of it. As well as some memories."
"Ah . . . the fault lies with me. For . . . both of those."
"Does it?" Severus surreptitiously slid his wand into his hand, though what he could do if the ghost really attacked him, he did not know. "How so?"
"I am . . . unsure."
"Funny, that's what Potter said. He remembers you flying through him. . . ."
"I did not . . . fly through him."
"No?"
"I possessed him."
"I see," Severus said, though he did not. He kept his expression carefully blank, and did not lash out as he wanted, but . . . What in the world was going on here? "May I ask why?"
The Baron's face matched his for blankness, though there was a flash of something in his eyes. "He is a Slytherin."
"Yes . . ."
"I did not expect it."
Join the bloody club, Severus thought. "That's not an answer."
"There was no time."
Getting the odd sense he was holding more than one conversation here, Severus said, "No time for what?"
"To aid him . . . in any other way. . . . He is powerful, but weak yet."
Dammit, this was getting him nowhere. "So . . . Potter was in trouble and you possessed him in order to aid him?"
A ghostly sigh toughed his ears, as if the Baron was pleased he had reached the correct conclusion. "He wishes to return," the Baron said in that same oddly flat tone, but there was nonetheless a note of urgency to his next statement. "And we cannot let him."
"Potter?" Severus shook his head, even as the Baron did. "You mean whoever attacked Potter. And someone did attack him, didn't they?"
"Yessss."
"Who?"
"I cannot say."
Severus frowned. What was this, then? "Are you unable to say? That is, whoever attacked the boy . . ."
"Confunded us, yesss. After we blocked or repelled his curses many times." The ghost almost smiled, a sight Severus never wanted to see again, he was sure. "Then we drove him away."
"How?"
"I . . . we . . ." The pale being looked down at his silver-blood covered hands. "There may have been fire."
"Fire."
"Yesss. And . . . a wind. I cannot be sure."
Severus snapped, "I expect it's a bit of a blur, is it?"
"Indeed." The ghost did not appear taken aback at all, but almost . . . repentant. "I had to Obliviate him, you understand."
"The boy."
"Yesssss. I was in control . . . he would have . . ."
"Dealt poorly with the aftermath." Severus sighed and barely refrained from rubbing at his temples in annoyance. He had no doubt at all that if the Brat had known he had been possessed by a ghost, even if it was to help him fight off an attacker, he would have caused even more of a scene. And likely exacerbated the damage already done to him by the "many curses" thrown at him. "And the wound?"
"I did not mean to leave it behind."
"It was yours? You left your own wound on him when you left his body?"
"It was not my intent." The Baron twisted his hands around, so Severus could see the blood on them. "But I have . . . not done such a thing before. He has recovered, you say?"
"He has. Although, not the memories." He had another way to get at them, but he had not wanted to use it. Not without Dumbledore's permission, at any rate.
The ghost's mouth pressed into a thin line. "Leave them be. He will not do well with that, Severus Snape."
Severus growled, "He will be attacked again and again, unless we discover who was behind this."
The Bloody Baron nodded tiredly. "He will. But . . . let me . . . speak to him first."
"Speak to him? That is all?"
"I do not like this gap in my knowledge," the Baron admitted. "But he is a Slytherin . . . I will not cause him further harm."
Severus regarded him for a long time, judging the verity of his claim. He had known the Bloody Baron a very long time, since Severus had been a child here, in fact, and he had never known the ghost to do anything remotely anti-Slytherin. And though he was usually taciturn, the Baron was not known for saying things he did not mean. "Very well. I should like to be present for this discussion, however."
The Bloody Baron nodded and started to fade backwards, down the corridor.
Severus halted him with a, "Peeves has been quite the troublemaker while you've been away."
The expression on the Bloody Baron's face shifted so quickly that Severus had to keep himself from taking a step back in fear. Rage and a promise of vengeance to come carved into the translucent form like wire. "I was . . . recovering, as well. I shall see to Peeves."
With that, he vanished entirely.
Severus went to the Headmaster immediately, and made a report.
That evening, the Brat showed up on time, with a scroll of parchment that he handed over without a word. His gaze remained on his feet.
Severus put down the scroll. "In my classroom is a bucket of murtlap tentacles which need to be pickled. First, you will cut them in the way specified by my written instructions, and then place them in the vat of brine. Any questions?"
"No, sir."
"Did you check in with Madam Pomfrey today?" He already knew the answer, having received a confirmation from Poppy, but he wanted the boy to acknowledge his own success.