Minerva McGonagall stood beside Poppy and watched as various coloured symbols flickered over the young man standing in front of Albus’ desk. There was something very strange going on here. She had taught James Potter and Sirius Black for seven years, and been their Head of House for that time. She had also worked with them for four years in the Order of the Phoenix before that disastrous Halloween night.

This . . . imposter certainly reminded her of both of them, but there was someone else in the mix. Someone that Minerva was sure she should know, but couldn’t put a name or face to.

“Is something wrong, Poppy?” Albus asked eventually. He absent-mindedly popped a lemon drop into his mouth.

“This just does not make sense!” Poppy exclaimed in frustration. “I’m getting conflicting readings from everywhere. For instance, my scans say that his collarbone has never been broken, had one clean break, and was broken into three pieces.”

Out of the corner of her eye, Minerva saw Sirius twitch, and start to raise a hand to his own collarbone.

“I’ve never broken my collarbone,” the young man said, then he grinned and his voice changed. “Had to have my arm immobilised for three weeks when I crashed my broom. Still saved the quaffle from Reggie, though!”

There was a short pause. “Hmm, yes, well, all of my scans say the same thing,” Poppy continued. “Either this man is a physical impossibility, or he’s three people at once . . . which is also impossible.”

“So we are still no closer to discovering the boy’s true identity.” Albus looked disappointed.

“Aren’t the records in some sort of database somewhere?” Harry asked. “Couldn’t you just . . . look them up?”

Minerva snorted as she saw Albus and Poppy mouth “Database?” to themselves. Sirius also looked faintly confused – as though he’d heard the term before but couldn’t remember what it meant – but Remus and, interestingly, the surprise young man, looked as if they knew exactly what Harry was talking about.

“I’m afraid, Mr Potter, that the Wizarding world hasn’t quite gotten that far yet,” Minerva explained. “But it was a good idea all the same. 10 points.” It wouldn’t even make a dent in the negative score Severus had plunged Gryffindor into, but it was a start, she thought. Everything had to start somewhere.

Nobody saw the brief flash of absolute hatred that passed over the young man’s face, apart from Fawkes, who began an almost inaudible calming trill.   

“Okay, but there are records, right?” Harry looked at Madam Pomfrey for confirmation. She nodded at him. 

“Indeed there are, Mr Potter, but considering how many years Hogwarts has existed, then there are thousands of student records.”

“Not to mention staff records,” Professor McGonagall added.

“Couldn’t you just summon them?” asked Harry. “Say, summon the records that include a broken wrist, then from that lot summon ones that include a broken collarbone, and so on. Wouldn’t that eventually only leave you with one?”

There was a pause as Madam Pomfrey considered this.

“It would still be an excessive amount of records,” she said doubtfully.

“But we could narrow it down, time-wise,” Remus suggested. “It’s obviously someone who was very familiar with both Sirius and James.”

“That someone is still in the room, you know,” interrupted the visitor. His arms were folded across his chest and he looked vaguely annoyed.

“Apologies, dear boy. Lemon drop?” Albus held out the tin. It was apparent that the stranger was having a brief internal struggle before he finally accepted one, although it was clear he hadn’t quite meant to, since twice he raised it to his mouth and then lowered it again, before stashing it in a pocket of his robes. “Unfortunately, though,” Albus continued, “unless you’ve remembered something that would help us?” He paused, and the stranger quickly shook his head. “Then I’m afraid we must continue to discuss you as though you were not here, until such time as you can make your explanations yourself.”

Remus cleared his throat as the young man sulked. “As I was saying, I think concentrating on the years we attended Hogwarts, with maybe a few years either side just to be sure, would do. I doubt anyone older or younger than that would have paid much attention to either James or Sirius, unless they were pranking someone.”

The young man bowed his head, but otherwise didn’t make any attempt to disagree or interrupt.

“Then that is what Poppy shall do,” Albus stated, smiling at the group. “Minerva, if you could see to organising rooms for our young Mr Black, and escort Harry to his next lesson . . . ?”

“Of course, Headmaster. Come along, Mr Potter, Mr Black.” Minerva gestured for them to precede her out of the office.

“Remus, if you and Sirius could carry on searching . . .” Albus continued behind them. The rest of his sentence was lost as the spiral staircase carried the three down.

After a week, Madam Pomfrey hadn’t made much progress with the records, as she was kept busy with injured students. Harry knew this, as he was one of the injured.  

The temporary Potions professor hired by Professor Dumbledore lacked Snape’s knowledge and talent – both in Potions and maintaining discipline in the class. Three separate exploded cauldrons had landed half the fifth year Gryffindors and Slytherins in the Hospital Wing.

The only positive thing about the woman, Harry mused, was that she didn’t appear to be working for or with Voldemort in any way.

Madam Pomfrey came bustling over to his bed, carrying a small vial of a pink and violet coloured potion. “Now then, Mr Potter,” she said cheerfully, “how are you feeling?”

Harry responded with a string of chirps and squeaks, which the enchanted parchment on the bedside table translated as, “I’m feeling much better, Madam Pomfrey.”

“Good. Drink this, and you should be back to normal by tomorrow morning.” She handed the vial to Harry, who made a face but drank it in one go. “You have a visitor,” Madam Pomfrey informed him, taking the empty vial back.

Harry looked beyond her, and saw Remus standing at the end of his bed. He grinned, and let out a stream of clicks and trills. Remus obviously hadn’t been told what had happened, as he looked considerably taken aback. Harry rolled his eyes and tapped the enchanted parchment.

“What happened?” Remus asked, seating himself on the bed.

“We – my group – were brewing a Transformation potion, and someone—” Harry very carefully didn’t look over towards the Slytherins “—tossed a jaymouse feather in our cauldron.” He indicated the feathered-and-furred Gryffindors in the nearby beds. “The new professor didn’t know what to do to stop it exploding. Nor any of the others.”

“Oh dear,” Remus said. He seemed torn between concern and amusement. “No-one was seriously injured?” Harry shook his head.

“Any luck with the search?” he asked, wanting to change the subject. He was sure Hermione would bombard him with all the things he should have done, but she had been caught in the line of fire when Goyle – or perhaps Crabbe – had added one too many ingredients in the wrong order, and created a volatile destabilising potion. Hermione and half a dozen others were all currently locked in a specially warded room, constantly changing from solid to liquid to gas, and back again.

“No, no luck at all,” Remus said. He definitely looked concerned now. “We even checked . . . it’s home location, but no-one’s been there for months.”

“Do you think Voldemort found . . . it?” asked Harry.

Remus shook his head. “We would know by now if he had,” he said reassuringly. “Has . . . Dumbledore’s visitor remembered anything yet?”

“No. We’re all calling him JB now,” Harry informed him. “Professor McGonagall said it was too confusing otherwise.” Remus made a murmur of agreement. “What about the records?” Harry continued. “Madam Pomfrey won’t tell me anything.”

“Probably because there isn’t anything to tell,” Remus suggested. “She hasn’t even finished the first lot of summoning.”

“But it’s been a week,” Harry protested. “How could there be so many people with the same type of injury?” Remus gave him a pointed look, and Harry remembered why he ended up so often in the Hospital Wing – besides Voldemort. “Oh.”

“So has . . . JB been put in classes?” asked Remus.

“Yeah, he got placed in our year,” said Harry. He frowned. “It’s weird, though. One day, he’ll be ace at Transfiguration, the next at Potions, then Defence, then flying, then back to Transfiguration. And he keeps making all these plans to prank people, but never does anything, although I think Fred and George are taking notes.”

“Oh, dear,” said Remus, looking a lot more worried now, obviously recalling some of the pranks the Marauders had thought up. “Perhaps I’d better get Minerva to have a word with them.” He got to his feet and patted Harry’s leg. “I’ll see you soon, Harry.”

“Bye, Remus. Say hi to Snuffles,” Harry responded, then snuggled down to sleep, as Madam Pomfrey lowered the infirmary’s lights, letting out the odd intermittent chirp or squeak as he dreamed.  

Two days later, Harry was back in his classes, along with most of the others who’d been in the Hospital Wing with him. Only three students hadn’t been released yet, as they’d had the misfortune of being hit by all three exploding solutions.  

“That woman is a menace,” Hermione fumed now, dropping her Transfiguration books onto a desk with a bang. “We’ll never learn anything if we keep ending up in the Hospital Wing. And then how will we pass our O.W.Ls?”

“So it doesn’t matter if we’re gravely injured, just whether we can learn stuff?” Ron asked, raising his eyebrows at Hermione.

“Of course it matters, Ronald!” Hermione huffed at him, as Harry stifled a laugh.

Professor McGonagall entered at that moment and began returning their homework assignments and passing out the woollen mittens they’d be attempting to Transfigure today.

“She might have a point, you know,” Ron said in an undertone to Harry. “Snape might be a greasy git, but at least less people get hurt.”

Harry nodded his agreement. Three more classes had been injured by exploding potions. One of the classes had been the first year Gryffindor/Hufflepuffs, and they had been brewing a potion that was so notoriously stable that it could even be brewed in a moving carriage.

A sound of frustration drew Harry’s attention to his right, where JB was stabbing his wand viciously at his mitten. They were supposed to be turning the mitten into a live rabbit, and then turning that into a wooden bracelet, but today was obviously not one of the days where JB seemed to Transfigure things as naturally as breathing.

Harry studied JB out of the corner of his eye as he poked his wand casually at his own mitten. The young man’s appearance had settled down. Only his hair continued to change, although never by more than an inch or so. He still had one hazel eye and one blue-grey eye. Madam Pomfrey had decided that although glasses were needed for his hazel eye, the resulting strain would be too much for the other eye, so she had charmed a clear, glass-like patch for JB to wear. He had complained it made him feel like a pirate, but hardly anybody noticed it.

“Is there a problem, Mr Potter?”

Harry jumped, and looked up to meet Professor McGonagall’s gaze.

“Ah, no, Professor,” he said.

“Then kindly carry on with your work,” Professor McGonagall said briskly, and turned away to where Neville’s mitten was trying to strangle Seamus. Harry looked at Hermione, who was wearing and admiring an intricate wooden bracelet, and Ron, who’d managed to produce a large rabbit that was still made of wool, and gave a sheepish grin.

An angry “Merlin scorch it!” and a frustrated hiss caused Harry to look at JB again, just in time to see a rabbit’s leg slowly morph back into the mitten’s thumb.

JB let out a stream of angry muttering, most of which Harry didn’t catch. But the couple of phrases he did hear confused him, as they sounded very familiar, although he couldn’t remember why.

Harry puzzled over it for the rest of the day, until he found himself after dinner sitting in the Gryffindor common room. A little to his left, a group of first years were complaining about the new Potions professor.

“Snape might call us dunderheads, but at least our potions don’t explode so much,” said one.

“And if they do, Snape doesn’t dance around, waving his wand, and make it worse,” another agreed, and they all snickered.

Harry sat upright, as their words washed over him. He shot to his feet and bolted for the portrait hole, ignoring the collective chorus of “What’s wrong? Harry!”

It was, perhaps, a miracle that Harry didn’t break a leg or his neck as he raced down the stairs and along to Professor McGonagall’s office. He barely remembered to knock and wait for her call of “Enter!” before bursting through the door.

“Professor!” Harry panted, gripping the front of her desk to keep himself upright. “I’ve figured it out. I know who JB really is and where Professor Snape is!” 

Albus was sitting at his desk, trying to conquer the ever-growing pile of paperwork, when Minerva brought Harry to his office. 

“Ah, Minerva,” he said, greeting them both with a smile of genuine relief as he put the current Ministry decree aside. “And Harry. Shouldn’t you be in your dorm, dear boy?”

“Mr Potter says he knows who JB is,” Minerva informed him. “And where Severus is.”

Albus’ bushy eyebrows rose almost to his hairline. “Well, that’s wonderful news,” he enthused, but then remembered just who could have Severus, and his enthusiasm waned. “Was it a vision, Harry?”

“No, Professor,” Harry answered. “It was JB, actually.”

“Really?” Albus frowned in confusion. “But how would he know where Professor Snape is?”

“He didn’t tell me,” Harry clarified, “but he’d know because he is Professor Snape!”

There was a shocked silence, and then “He’s what?” burst from Minerva. Albus held up a hand to forestall any comment she might make and turned his full attention to Harry. “Please explain how you came to that conclusion, Mr Potter,” he said.

“Well,” Harry twisted his hands together, nervously. “In Transfiguration today, JB was having problems and getting really annoyed, and he started muttering to himself. I couldn’t hear all of it, but it included ‘dunderheads’ and ‘foolish wand-waving’. Then the first years were talking about the new Potions professor after dinner, and said both phrases, and I remembered the speech Professor Snape gives in first year.” Harry fell silent and chewed on his lower lip.

“Hmm.” Albus folded his hands together on top of his desk. “I suppose there’s only one way to find out if the young Mr Black is truly Severus. Minerva, would you fetch him, please?”

“Of course, Albus.” Minerva headed briskly for the door, and Albus waved a hand at a chair in front of his desk.

“Sit down, Harry,” he said, and watched as Harry carefully sank into the comfy armchair. “Lemon drop?”

“Ah, no thank you, Professor,” Harry declined, shaking his head.

Aside from soft coos from a Fawkes busily preening his feathers, they sat in silence until Minerva returned with the strange young man who could be their missing Potions Master. JB looked curious, but not unduly worried.

“Take a seat, dear boy,” Albus invited, cheerfully. “Now, we believe we may have discovered your true identity.”

“Really?” There was a faint hint of anxiety in the word, and Fawkes abandoned his primping to fly across and land on JB’s shoulder. Trilling a calming melody, he rubbed his head against JB’s cheek.

“Yes. We believe you are actually Professor Severus Snape,” Albus said, watching the boy closely. It was impossible to miss the panicked terror that flared across his face. Fawkes trilled louder.

“But . . . no!” the young man exclaimed. “I’m James Black. Sirius Potter. I’m Sirius James Potter Black!” He shot to his feet, ignoring Fawkes who had sunk talons into his shoulder to remain on his perch, and tried to bolt for the office door, only to be stopped by spells from both Albus and Minerva blocking his way. He turned around to face them again, tears flowing down his face. “I’m James Black,” he repeated, desperately.

“I’m sorry, my boy, but we must know for certain,” Albus said. He pointed his wand at the young man and began chanting a long stream of Latin.

JB shook his head frantically, and raised his arms as if shielding his head from an expected blow. A pale light surrounded him, obviously attempting to shield against Albus’ magic, but it was no use.

With one last blinding flash, the light disappeared, and with a terrible, heart-rending wail, the young man slowly shifted into the missing Severus Snape, and then promptly fell to the floor, unconscious.