The full moon came and went.

Remus' friends, to Remus' great relief, did not attempt to put Mandrakes in their mouths this month. Remus suspected it was because they needed a new plan over the summer when they could no longer access Hogwarts' resources. It was going to be a lot harder to sabotage them when they no longer shared a room with Remus, but Remus would try his best. He wasn't worried—not yet.

James sat in the common room with Remus before heading down to the Hospital Wing, and Remus managed to eat a small breakfast consisting of an egg and dry toast. That was a good sign. He made sure to write it in his notebook for future Arithmancy research.

He was in a relatively good mood when Madam Pomfrey walked him down to the Shack—still frightened out of his wits, yes, but overall all right. "I don't know why," he told Madam Pomfrey, "but being mostly done with exams while everyone else worries about them is incredibly refreshing. Lack of stress is always better when everyone else is suffering from the presence of it."

"You like watching them suffer," clarified Madam Pomfrey, and Remus giggled.

Despite his good mood, however, he ended up suffering a rather horrific injury somewhere during the night, and there was truly nothing like regaining one's human mind on the floor of a Shack and immediately starting to choke on one's own blood.

"Dear me," said Madam Pomfrey, rushing to his side. "What did you do?"

"Don't know," Remus wheezed. "Can you fix it?"

"Only if you stop talking, you insolent child."

He lied there, trying to breathe. After a while, he could feel the blood draining from his lungs, and then he was all right once again. "I think you scraped the inside of your throat somehow," Madam Pomfrey said with a frown. "Are you certain wolves don't kill themselves during full moons, Remus? You've said it many times before, but I feel certain you'd've died from this if I hadn't been there."

"I think that one was a mistake," said Remus. "I… I didn't mean to do that. I just accidentally swallowed a loose nail in the floorboards. It was a total accident. I was meaning to eat the wood, that's all. Helps the itching in my teeth."

"You ate a nail?" shrieked Madam Pomfrey, and then she rushed Remus to the Hospital Wing and put him to sleep. When Remus woke up, everything was all right once more, thanks to the lovely and talented Madam Pomfrey.

"I'll add that to my dietary restrictions," he mumbled. "No garlic. No wolfsbane. And no nails. Make sure to tell the house-elfs not to put nails in my food."

"I shall certainly do so," said Madam Pomfrey. "Now drink your water and eat your soup. I promise there are absolutely no nails hiding therein."

Remus did, and there weren't.

Remus stayed in the Hospital Wing for two more days, making it a total of four. His friends visited him every day, telling him all about exams and prepping for the next one. Finally, Remus could tease them for having to take exams while he had the week off, effectively exacting his revenge for their taunts the week prior.

The day he got out of the Wing, he received a summons from Professor Dumbledore to meet him in his office for his detention.

"Well, that's just lovely," he muttered, staring at Dumbledore's handwriting, hoping that perhaps, if he stared hard enough, then it would disappear.

"But you just got out of the Hospital Wing," said James. "And you have your History of Magic exam tomorrow!"

"Out of the frying pan and into the fire, I suppose," said Remus.

The next hour passed slowly—dread always seemed to make the clocks move like molasses. Remus didn't even have classes due to exams, so he spent his time in the dormitory, staring out the window and worrying. When the time finally came, he dragged his feet to Professor Dumbledore's office and knocked on the door. It was a good thing that humans couldn't hear heartbeats, because Remus' was going a mile a minute.

"Ah, Remus," said Dumbledore, opening the door for him with a smile. "Right on schedule. Come in."

Remus scuffled inside and sat on a chair, tapping his fingers on his thigh to curb the relentless anxiety coursing through his veins. "What are you going to have me do, sir?" he asked.

"If you would like, we're going to go on a short field trip today," said Dumbledore with a smile. "You see, I've been asking your friend Sirius to help me out with my headmaster duties so that I could attend to things more pressing. Namely, the war. Dark activity is spreading throughout the nation like wildfire, Remus, and I am expected to keep as much of it at bay as possible."

"But… but you're busy! You have another job!"

"Yes, and it is a job I very much enjoy. But, as a powerful wizard who once defeated another major Dark force, there are certain expectations that I must uphold. I am the only one who can do these things, so I do them. Otherwise, people would die."

"So… what do you need me to do, sir?"

"Well, Remus, here's the thing." Dumbledore leaned forward slightly and steepled his fingers, a sign that he was about to disclose something very important. From the look in his eyes, Remus did not think he was going to like it. "You have a full week of detentions, and for the most part, I'm going to have you do mundane detention things. I'll have you clean the trophy case, perhaps, or pick weeds in the greenhouses. But today is different. Today, I genuinely need your help. And, unlike most detentions, you are perfectly allowed to decline my offer of the field trip—in fact, if you decline, then I will allow you to go back to your dormitory, and we'll merely pretend that we did a detention today."

Remus tapped his finger on his thigh more quickly. He really did not think that he was going to like this, judging by the cautious look Dumbledore was giving him.

"I do not wish to use you for your… unique abilities," said Dumbledore, "but I do, unfortunately, require them. There is a house south of Paris which I believe to be housing a hostage. I have been watching the house, of course, and I don't believe anyone lives there. Last time I entered to look for the hostage, though, I was met with no luck. The charms are powerful enough that I cannot cast anything to help me find her, and my guess is that she is behind some sort of secret entrance. I will find her without your help, Remus, so you need not agree to do this. But if you do, then I'm sure it will be much quicker."

"Sorry," said Remus, "let me clarify. You want me… to sniff her out?"

Dumbledore's expression remained impassive. "More or less."

Yeah, Remus didn't like that. He wrapped his arms around his stomach and drew in a very slow breath. Could he do this to save a hostage? Yes, Dumbledore would find her on his own (eventually), but how long had she gone without food and water? Remus needed to help, didn't he? Even though he didn't want to be treated as a personal bloodhound… it made him feel so animalistic and inhuman.

But he could help out. He needed to.

"Yeah, I'll help," he said, and Dumbledore smiled.

"Excellent. Rest assured that I will allow no harm to come to you. As long as you are with me, you are safe… no matter what happens. Yes?"

Remus nodded. "Yes."

"Good. Do you have your wand?"

"Yes, sir."

"Ready to go?"

"Right now, sir?"

"Yes, of course. I was under the impression that you don't have any classes today. It's a nice little side effect of taking your exams a week early, isn't it?"

Remus nodded again, and he watched as Dumbledore stood up and held out his arm for Remus to take. "Last chance, Remus," he said. "There is absolutely no judgement if you wish to write lines today instead."

Remus considered that. Overall… yes, he'd rather be writing lines than being used for his werewolf sense of smell and hearing. He didn't want to do this at all. But he wanted to help, of course, and his mind kept drifting back to how thrilling adventures often were once Remus got over the initial hump of being afraid. He stood up, smiled, and grabbed Dumbledore's arm—a moment later, he was hurtling towards nothing and everything.

"Here we are." Dumbledore gestured to the house. It was a very normal house: quaint, small, and exactly the same style as every other house in the area. It was so regular that it was almost outstanding; Remus was certain that anyone who walked past it wouldn't venture to look at it twice.

"How do you know this is the correct house?" he asked.

"Ah, yes," said Dumbledore, unfazed as ever (even when looking directly into the eyes of a house that might very well be a place for keeping hostages). "That is important, isn't it? Let me tell you about the hostage we are seeking."

He put a hand on Remus' right shoulder and led him toward a secluded place behind another building. There were two rather large rocks, and Dumbledore sat on one and beckoned for Remus to sit on the other. "The hostage in question goes by the name of Marlene McKinnon," he said. "She's a very talented witch who worked as a Healer for a time in combat. She was taken hostage by Death Eaters about a week ago, but she managed to notify me of her location via owl right before we lost all contact with her. I am certain that she was, at least, in that house. Whether she is still there is something that I need you to confirm for me."

"All right," said Remus slowly. "And the house is safe?"

"Indeed it is. I've entered myself a couple of times. As I have told you before, Remus, you are safe as long as you are with me."

"Okay. So I'm looking for a woman… what's the age range?"

"Thirty. I'd like to find her as soon as possible, both for her own sake and for the sake of her husband and young daughter."

"All right." Remus breathed in through his nose, out through his mouth, and then said, "Let's go, then."

Dumbledore smiled, stood up, and led Remus back to the house. "I need you to stay behind me," said Dumbledore. "Last time I visited, there were no Dark spells, curses, or jinxes whatsoever, but there might very well be this time. Stay calm, if you please."

Remus watched as Dumbledore turned the silver doorknob and opened the door—it creaked as it slid open, almost as if it was protesting their entrance. Suddenly, Dumbledore stopped and turned toward Remus. "Anything?" he said.

Remus remembered what he was meant to be looking for. "Not yet," he said.

Dumbledore nodded, and then he stepped into the house. Remus followed him. It was dark at first—there seemed to be a charm obscuring the light from the windows from reaching all the way into the house—but once Dumbledore lit his wand, the entire interior was beautifully illuminated.

It was furnished fully, which Remus hadn't expected from an uninhabited house built solely to hold a hostage. There was an ornate rug spread across the floor, and the chandelier on the ceiling dripped with blue jewels and golden metal. Lamps were on the walls and the tables, and they looked horribly expensive. There were gorgeous picture frames on the walls, but nothing was inside them.

"Anything?" Dumbledore asked.

"Nothing," responded Remus. "But… there's some sort of… wait. Could you be quiet for just a second? Stop breathing."

Dumbledore obeyed, and Remus listened.

There was a definite buzzing, though it was faint enough that Remus couldn't quite tell where it was coming from. It reminded him of something… he couldn't quite place his finger on it, but it was definitely familiar.

Suddenly, he remembered. He remembered sweating through his robes, standing in the green grass on the Hogwarts grounds with Miles and Peter, who was holding an enchanted (cursed) basket. He remembered Hagrid's pumpkin patch. He remembered the buzzing, and it was exactly like this.

"There's some sort of concealment charm," said Remus. "I'm not sure exactly what it is, but it reminds me of the one Dilley put on Hagrid's pumpkin patch during the egg hunt. Can't you hear it?"

Dumbledore leaned closer, and his clear blue eyes were sparkling like the blue jewels in the chandelier. "Remus," he said slowly, "are you telling me that you can hear concealment spells?"

"Only when it's very quiet."

"That is… very helpful."

"Miles and Peter said that they could see the concealment charms on the pumpkin patch, though. Can't anyone see them?"

"Some can. Mostly children. Adults have a much harder time seeing the slight shimmer of a concealment charm, and even children and those with keen eyesight often don't see them unless they know where to look. But you can find out where to look, can't you?"

"I don't know where it is. I can hear it, but it's not… obvious. It's very faint."

"Do you think you'll be able to figure out where it's coming from if we get closer?"

"I think," said Remus.

They started walking around slowly, and Remus noticed that Dumbledore had slowed his breathing, taking large intervals between each quiet breath. It helped a bit. They went from room to room, admiring the ornate furnishing and listening for the buzzing, faces illuminated by Dumbledore's wandlight. "It's almost like electricity," Remus whispered, "but fainter and… higher-pitched, if that makes sense."

"Is it growing stronger or weaker?" asked Dumbledore as they approached the kitchen.

"Weaker. I think it was closer to the sitting room."

They walked back to the sitting room. "Do you think that a concealment charm placed more effectively by a more skilled wizard would be fainter?" Remus asked. "I don't remember Professor Dilley's charm being this quiet."

"Yes, I think Professor Dilley cast it to be slightly more obvious on purpose. Whichever wizard cast this was not casting to play games; he (or she) was legitimately casting to conceal. I'm not surprised it's fainter than Professor Dilley's was. The shimmer must be nearly nonexistent. Do you think the charm is in this room?"

"I… I don't know. I don't know what it sounds like at its loudest, sir. But it wasn't any louder in the other rooms, and I don't see why anyone would place the hostage in the very first room through the front door… ARGH!"

Remus' head was on fire. His ears were burning. He could hear nothing but pain, because apparently pain had a sound, and this was it… it wasn't anything that Remus could place, exactly, but it was noise that wasn't noise, and it was filling Remus' head and turning his brain to gelatin, and his skull was surely going to explode, and…

Suddenly, the sound shut off. Remus' head cleared. He opened his eyes, groggy, and realized that he was kneeling on the floor. There was a hand in front of him: he took it, and Dumbledore hauled him to his feet with surprising strength for someone so elderly.

"What was that?" Remus mumbled.

"I believe it was a jinx," said Dumbledore quietly, "but for some reason, it only affected you."

"You didn't… hear that?" Remus was still panting. His ears rung slightly, which made it very difficult to hear the buzzing of the well-hidden concealment charm.

"No. I heard nothing. From my perspective, you merely dropped to the floor for no reason whatsoever. I managed to undo the jinx, of course, before it caused too much damage… if that was its intention. Perhaps it was harmless. At any rate, a few counterjinxes successfully broke it. How are you feeling?"

"Fine, I guess. That hurt, though. I wonder why it didn't affect you. Do you think it was an age thing?"

"Perhaps…" Dumbledore broke off into thought, staring at the carpet. "Remus, once again I must ask too much of you. Would you mind risking experiencing that again for me? Only for a moment. You are, as always, allowed to say no."

"Erm… why?"

"So that I can confirm what it is. I will undo the spell after three seconds maximum, I promise. I merely want to… test something."

Remus sucked in a deep breath. "All right," he said. "How bad could it be?"

"Do you see that small lump on the rug? I am going to step on it. If it's a localized jinx, it will only affect me. However... if I am correct in my theory, which I usually am, you are about to be very uncomfortable. Are you ready?"

Remus took another deep breath—in through his nose, out through his mouth—and then nodded. Dumbledore took a few steps forward.

Suddenly, pain flooded Remus' head, making it feel so painfully full that he was certain he'd gained at least two stone. He managed to stay standing, but he found himself gripping the arm of the couch… the sound of pain was loud and incomprehensibly overwhelming.

It stopped.

Remus realized that the thing he'd been gripping had not been the arm of the couch: it had been Dumbledore's forearm, but Dumbledore didn't seem to mind. "Are you all right?" he asked.

"Yes," said Remus. "Did you… find out what it was? Or do you need me to do it again? I will, you know—it's way better than a transformation, so I can handle it as many times as you want me to."

"I would never ask you to do it a third time," said Dumbledore lightly. "Asking you to do it a second time was morally questionable enough. I did, however, find out why you were affected so, and I believe I've learned some very valuable information."

"Will you… tell me?"

"Of course. While I am explaining, I would like it if you'd help me move this furniture aside. I believe what we are looking for is under the rug. Please be careful not to touch any of the lumps in the rug."

Remus started moving furniture, and Dumbledore began to explain. "What you just experienced was a magical sort of ultrasound," he said. "It was a frequency so high that I could not hear it, but your enhanced hearing managed to pick up on it at a painful level."

"Like a dog whistle," Remus grumbled, carefully levitating a lamp out of the way.

"A little. Magical ultrasound at the decibel level that you just experienced, however, would be dangerous to humans after prolonged exposure. Even though I could not hear it, it would have damaged me after a while. The jinx producing the ultrasound, I have to admit, was very clever. It is a way to impair without detection. If you had not been with me, I might very well have noticed too late."

"You… would have died?"

"Probably not at that level, but I would have certainly been uncomfortable and much easier to beat in a duel… although, forgive my arrogance, but I think I could win even when uncomfortable and impaired. You really do have extraordinary hearing, Remus."

"I know." Remus couldn't help but be a bit scornful. "It's not something to be proud of."

"On the contrary. It does not make you less than human, Remus—it makes you more than human, and extraordinary abilities do not make you less of a person. You can hear things no one else can. You can eavesdrop behind multiple closed doors. Your ability to distinguish pitch is remarkable. Your—"

"Wait," interrupted Remus. "I can't distinguish pitch better than anyone else can."

Dumbledore paused and looked at Remus. "Yes, you can."

"No, I can't. I'm a terrible singer."

"You can," said Dumbledore with a smile. "Now I would like you to take my arm, Remus, and I will take you back to Hogwarts for your afternoon meal. Thank you very much for indulging me."

"Wait! But… where's Marlene McKinnon? Isn't she here? I can smell someone, I think, but only faintly..."

"I believe she is just behind this nearly-airtight trapdoor." Dumbledore gestured to a small trapdoor underneath the newly-moved rug with his toe. "Move a bit closer to it. Does the buzzing get any louder?"

"…Yes."

"I believe the concealment charm is behind this door, but I do not wish for you to see whatever is down there. It may be dangerous, and it may be gruesome—though I pray it is not. There may even be a Death Eater down there. No, I would very much prefer to find Marlene on my own, knowing that you are safe and secure within the walls of Hogwarts. May I?"

Dumbledore held out his arm, and Remus took it—Remus' insides curled in on themselves, and then they were back in Dumbledore's office. "Thank you very much for your help," said Dumbledore. "You're dismissed, Remus—I am going to rescue Marlene. Please be back here tomorrow at ten o'clock for a detention activity that will be… much more boring."

Dumbledore Apparated away with a pop, and Remus left his office and started walking back to the dormitory.

Best detention ever, he thought fervently.