Harry was preparing to leave Grimmauld Place after having lunch all by himself. He and his fellow Auror trainees had the same morning completed the first part of the November preliminaries of the Auror program and had been given a few hours to recover before returning for the remainder of the examination in the afternoon. Ron, Dean and Seamus had gone to Dean’s place to have lunch and relax a bit, but Harry had wanted to see if Ginny was awake at home, and steal a moment with her. She had still been fast asleep, however, and Harry had not wanted to wake her up. He had eaten and then laid down and rested next to her for an hour. He had slumbered and still felt drowsy and slow, but needed to pass St Mungo’s quickly on his way back to the Ministry, so off he went by Apparition.

The physical test had been extremely hard – Harry already felt the upcoming stiffness from excessive exercise in his muscles. It seemed to Harry that Walter had focused on raw physical strength in the examination and it appeared to be Harry’s weakness. He regretted being a bit thin, but it seemed impossible for him to gain weight for a durable time. Years of wrestling and running away from his cousin Dudley, and another set of years with quidditch training had made him resilient and hardy, however, and his stubbornness served him well, too. So he had passed, although several of his fellow students who had spent the last few weeks building muscles specifically for this test had done better. Ron was one of them. Being both tall and now with quite a coat of muscles on his body, he received the next highest score on the physical test. Harry was happy for Ron’s sake, but consoled himself with having won an easy victory on the steeple chase course where they had been allowed their wands; Harry being both fast, quick in judgement and nimble with his spells.

Harry was expediently in and out of St Mungo’s, and was subsequently going to Apparate to the Ministry, but once in the Apparition hall of the hospital, he suddenly felt like walking a bit. He frowned at himself, trying to shake off the remains of sleepiness – why did he feel like walking? The weather was terrible and he would be late. It was raining outside, so Harry brought out his wand to cast an Impervious spell on himself. He felt a reluctance to do so, but why should he? He would be soaked if he did not. He cast the spell and proceeded through the door out on the Muggle street, when the realization hit him: Someone was trying to Imperius him. They wanted him to walk on the streets, and they wanted him to get soaked.

A shiver of terror blazed through Harry’s body. Who was it? He cast discrete glances around him, but continued to walk. Let them think that they had succeeded in controlling him, partially at least. There were only Muggle clad figures on the pavement around him, but he thought that he perceived a somewhat familiar magical signature nearby. Harry walked on, thinking fervently about what to do, who to alert.

He suddenly felt a strong urge to contact Snape and to warn him. But this must be the Imperius acting upon him, he realized almost immediately. Snape would be safe at Hogwarts. It was not logical at all that Harry would feel a need to Apparate to Spinner’s End that Snape visited very seldom anyway. And Apparating to Spinner’s End, if Harry was being traced, would only serve to unveil the location of Snape’s residence which was since August under a Fidelius protection. Harry had been trusted by Mrs Steadfast to be the Secret keeper of Snape’s home. Harry felt a surge of terror – it was of the utmost importance that he resisted the Unforgivable curse and did not betray Snape.

Was this Bellamy Burgess trying to get at Harry and Snape? But Harry thought that he would recognize Burgess’ magical signature from last year, and he did not. Could it be Hades Hatch, or Henna Hatch? What did they want? Why not simply try to kill him? Probably because they wanted Snape as well, and they wanted Voldemort’s note book, Harry realised.

Harry knew from before that he was able to resist the Imperius, and what happened right now confirmed this fact. He could feel waves of compelling forces pour over him, but he was at the same time master of his own will. He was scared, though. What would the persons do when they realized that he did not obey?

Harry decided to Apparate to the Ministry. Although he was sure of being traced, he thought that by entering the building quickly he would increase his chances of giving the alarm. He Disapparated suddenly, in the middle of a step, and Apparated with extreme precision in the Minstry’s common entrance, only one step from the security guard, and hissed a warning to the wizard, never really letting go of his wand during the security check. To his surprise, the guard did not seem alarmed, but winked at him and stated calmly that he would alert Mrs Steadfast at once.

Confused, Harry proceeded with caution to the elevator, staring hard at each of the wizards and witches who surrounded him, but comforting himself with the thought that an attack among so many bystanders was improbable. When the elevator stopped he hurried, alone, down the corridor to the Auror office with a sense of impending relief.

The door to Mrs Steadfast’s office was closed so Harry entered the classroom next to the Aurors’ common room. The sight that met him made him stop dead in consternation.

All of his classmates, including Ron, Dean and Seamus were seated at their places, vague expressions on their faces, completely soaked with rain from top to toe. By Merlin, thought Harry. Every single one of us has been targeted. He was glad, though, for his classmates’ sake, because the fact that they had managed to make it to the Auror Office showed that they had in the end been able to escape the Imperius, did it not? But why did they not dry themselves up with a spell? He opened his mouth to say something to Ron, when Mrs Steadfast stepped into the room together with Snape.

Snape looked worried and wary. He lifted his eyebrows at the sight of the soaked students, subsequently narrowing his eyes with suspicion. Mrs Steadfast looked impassive, but was that the slightest twitch of amusement in the corner of her mouth? Harry riveted his eyes on Snape, confused. What was all this about? What if people were still Imperiused in this room? What if Mrs Steadfast herself was Imperiused?

Harry sought to catch Snape’s eyes. Watch out! Harry tried to send an image of alert to Snape. They had practiced silent communication only the other day. Snape looked at him attentively, appreciating that Harry was the only one who wore dry clothes, nodding imperceptibly and making a slight movement with his right shoulder. Harry followed the arm down to Snape’s hand where he perceived the tip of Snape’s wand hidden in his palm. Snape seemed to be prepared - he too suspected something. Harry already had his wand out openly.

“Children,” said Mrs Steadfast in a neutral voice. “We have a serious situation. We’re waiting for Walter in order to clear this up.”

“And here I am, Mrs Steady!” Walter stepped into the room, full of confidence and not looking in the least troubled. “Ready to solve all your problems!” The drawling voice did not stop Harry from being hit with an instant realization. He recognized the magical signature! He acted on instinct.

It’s him! Harry launched by thought to Snape, conveying the image of the American. The Imperius! Almost instantly he received in return an image from Snape of them attacking Walter. Harry confirmed readily with a grim nod, gripping his wand tighter.

Everything happened very quickly from there: Harry was in plain sight, so Walter had no problem defending himself when Harry attacked - it was expected, but Snape’s Expelliarmus came almost imperceptibly from the other side and Walter ended up disarmed and with Snape’s wand at his throat. Snape grabbed the wizard by the chest and dragged him backwards while a chocked buzz travelled through the room. Harry picked up both his and Walter’s wands that had dropped to the floor. He pointed them wearily at Mrs Steadfast.

“Harry, evacuate the room,” ordered Snape. “Get some help, but be careful – we don’t know how deeply this man has infiltrated the office and how many he has Imperiused.”

The students rose with confused expressions on their faces, but Mrs Steadfast stepped in, unafraid, between Snape and Harry.

“By Mars! You’re quick, you two!” She turned to the students. “Sit down, all. Please, Severus, Harry, this is only an exercise. It’s not for real. Walter is a true ally. Release him, please.”

Harry frowned and Snape narrowed his eyes suspiciously, not yet letting go of the American teacher.

“Check Mrs Steadfast for influence of the Imperius, Harry,” he said curtly. “She was acting strangely earlier.”

”By Saturnus, I had to conceal the procedure from you, Severus – the exercise wasn’t finished, even if you had resisted the Imperius.” Mrs Steadfast spread her arms out in an innocent gesture, and let Harry examine her.

“She’s not under its influence,” said Harry after having read a short incantation over Mrs Steadfast.  

Snape released Walter who looked a bit squashed. At least some of his show of superiority was gone as he cleared his throat and adjusted his clothes.

“Well…” he said. Mrs Steadfast suddenly giggled nervously.

”I think that you might’ve learned something in the bargain for once, Boss,” she said. “Come in you all!” She addressed several Aurors who had gathered at the door. They positioned themselves along the wall, some of them leering at the Auror apprentices. “You’ve all learnt to know Walter, our Physical Education trainer over the past few months,” Mrs Steadfast continued. “He’s a devoted athlete in every sense, but that’s not the whole truth about him. Everybody, please let me introduce Auror McSmithery from the MECUSA.”

A murmur went through the room, the students in their soaked clothes no longer looking only abashed, but excited as well, and several of the British Aurors straightening their backs.

The name rang a bell to Harry as well, but he did not feel in the least impressed. Now that the impending danger was gone, he felt anger mount in him. So Walter had worked under cover all this time. The Imperius had only been an exercise! Harry was only now able to appreciate how scared he had been during the last hour. Rage started to boil in him. Famous or not, he did not give a gnome’s toenail if this Auror was Dumbledore himself! Clenching his jaws he tossed his head at Auror McSmithery and flashed his eyes at Mrs Steadfast.

“Is it supposed to be a feat to cast Imperius first year students?” Harry spat. The others started at his outburst. “Did you know that your famous Auror took the opportunity to try to make me break the Fidelius and show him Professor Snape’s residence?” Harry launched at Mrs Steadfast. Walter McSmithery cleared his throat.

“This wasn’t only a first year preliminary test,” he said, his voice devoid of the slightly arrogant and drawling tone that he had maintained since he arrived at the office. He sounded much sharper now. Harry glared at him suspiciously. “You did extremely well to resist me, Mr Potter. We had heard the rumours of your ability to resist the Imperius, but we needed to test you. Were you even briefly under its influence?” He looked inquiringly at Harry.

“No, I don’t think so. I only walked on so that the person trying to Imperius me would think so and be off his guard,” Harry replied, still suspicious, but beginning to calm down.

“Very good, I wasn’t sure if I had a partial effect on you,” said McSmithery. “Most importantly, you did not betray your role of Secret Keeper. You on the contrary,” McSmithery turned accusingly to Snape, “you led me to Grimmauld Place! You’re not the Secret keeper, but you belong by special invitation to the inner circle. The professor was my first target today, then I picked the students one by one, ending with Mr Potter here. Mr Snape managed to slip out of the Imperius a little later on and I let him go, but he did betray the location first,” explained the American Auror. An impassive Snape lifted an eyebrow.

“Did I now?” he said. “I defy you to find Grimmauld Place based upon what I showed you.”

McSmithery narrowed his eyes.

“Based upon what you showed me? You led me there… We Apparated… I saw with my own eyes…”

“I’m sorry, Walter,” said Mrs Steadfast. “Professor Snape seems to have misled you. Severus came to my office this afternoon in a real state, warning me of the Imperius attempt, wanting me to send out squadrons of Aurors to protect Potter and his friends. I had to use all my ingenuity to calm him down. Severus apparently made some mind dodging thing to fool you, Walter. It’s his speciality. Apparently he betrayed nothing in fact, but let you imagine that he had.”

McSmithery’s mouth actually fell open briefly before he closed it and shook his head, colouring slightly. Snape lifted his eyebrows calmly. Harry felt a surge of pride on his professor’s behalf. Some of the others must have experienced similar sentiments, because Seamus muttered defiantly:

“Professor Snape fooled Voldemort himself, haven’t you heard?”

The soaked students straightened their backs. All confusion was gone from their faces by now. Auror McSmithery cleared his voice again.

“I can only congratulate you, Mrs Steady, on having such accomplished associates as Mr Snape and Mr Potter,” he said and bowed curtly.

“Walter has over the past weeks been assessing our entire group,” explained Mrs Steadfast. Her Aurors along the wall looked at each others. “Including loosely tied associates,” she glanced apologetically at Snape. “I’m very sorry that I’ve had to subject you to this scrutiny, especially since it was done in secret. The decision came from above and I had to carry out orders. It became evident last June that we had been infiltrated by someone who initially was associated with Voldemort and subsequently with the Shiftings group. I’m speaking of Bellamy Burgess who a lot of you knew and who we did not suspect until he betrayed us. His example made it necessary to cross-check the entire squad. Only someone from the outside could do it. The physical education training was a cover.”

“My mission has now come to an end,” Walter relayed Mrs Steadfast. “I’ve written my report in detail, and I’ve found no indications of further treachery. Today’s exercise with you lot ending up here soaked to your bone…” He looked at his students who lowered their heads. “…was a reminder not to let your success mount to your head. You all passed today’s physical, complying with basic protective behaviour, but as you can see, you’re still easy targets for a person willing to use Unforgivables.”

“That said, it’s useful to know whether you’re immune to the Imperius or not, and I’m sorry but it’s part of the Auror training to be tested for it,” said Mrs Steadfast.

“Immunity is extremely rare,” said Walter McSmithery. “It’s unusual to find three persons within one group.”

“Three?” asked one of Mrs Steadfast’s Aurors.

“Your boss has an innate immunity to the Imperius, as well as Mr Snape and Mr Potter,” said Walter McSmithery. “I should know – I’ve tested her multiple times when she worked with us at the MECUSA. With her independent personality it isn’t unexpected, perhaps.” There was a slight sarcasm in Walter McSmithery’s voice, but Snape looked appreciatively at Mrs Steadfast. “Do you know if you’re related in some way?” the American Auror turned unsuspicious to Snape and Harry. “Kinship might explain this statistical unlikelihood occurring,” he added. To his surprise sniggers were heard in the whole room and Snape and Harry both pulled wry faces.

“You didn’t follow the British press last spring, did you, Walter?” said Mrs Steadfast. “Professor Snape and Harry Potter were both accused of being Voldemort’s descendants, but it turned out to be entirely unfounded.”

“Some kind of distant relationship between the two of you, maybe?” muttered the Auror. “It’s extremely rare to find…”

“They’ve got a court order stating that they’re not kin,” Mrs Steadfast cut short, because she had noticed a heightened colour on Snape’s cheeks. It was true that last June at Severus Snape’s trial, the head of the Wizengamot herself had declared once and for all that Harry was the son of James Potter and nothing else. It had put an end to all the malicious rumours circulating.

“Now, you still have some theory to write,” said Walter McSmithery, giving up on the subject. “But first, you’re allowed a warming charm to dry yourselves up.”