The Forbidden Forest
It all started becoming a nightmare.
Filch took them to McGonagall's study on the first floor, where they sat and waited without saying anything. Chrys was staring at nothing, taking deep breaths to try and calm herself down while Arthur was thinking of what to tell McGonagall, when not telling himself off in his head. At first, he thought of making a cover up story but he quickly shot that down, knowing McGonagall will see past his lies.
McGonagall would find it hard to accept what he'd say because they were still out of bed at night, creeping around the castle and ended up at the tallest astronomy tower, which is out of bounds except for classes. He realised that he may as well tell the truth, hoping she'd at least understand.
Then suddenly, McGonagall appeared with Neville behind her.
"Arthur!" Neville burst out upon seeing him and Chrys.
"I was trying to find you to warn you, I heard Malfoy saying he was going to catch you, he said you had a drag-" Arthur shook his head violently to shut him up. McGonagall nearly saw this as she stood towering in front of them.
"I would never have believed it of any of you. Mr Filch says you were up the astronomy tower. It's one o'clock in the morning. Explain yourselves."
Arthur took a deep breath before he did it. He told her the whole story. That he, Chrys and David learned that Hagrid had an illegal dragon egg. How they tried to talk sense into him when the egg hatched, that they contacted David's brother, Kenny, to try and get the dragon out before Hagrid could get into trouble, that Draco had learned of this and planned to get them into trouble and he stressed that Neville was never involved with any of this at all. He, of course, omitted the part involving his Invisibility Cloak.
McGonagall looked at them in silence for a bit, clearly soaking in what he just told her before sighing.
"I see. Well, I'm not surprised that you and your friends would help Hagrid. However, it would have been much easier to talk to Professor Dumbledore to sort the whole situation out. And it would not have resulted in you going out of bed to do so." She said, sounding sympathetic.
"However, this doesn't change the fact that you still went out of bed and walked around the school at night, and therefore, I must give the three of you, yes, you too, Mr Longbottom, detention." She then said, her stern tone coming out.
"Yes, Professor." Arthur nodded, sounding so guilty yet relieved.
"And 45 points will be taken from Gryffindor." She then added, making the three students wince, especially Neville.
"We… understand, Professor." Chrys said, not wanting to argue against her and get her in a bad mood.
"I would suggest not talking about what happened to the rest of the school. Now, go back to bed, all of you." McGonagall then said.
Fourty five points lost. Gryffindor still has a chance to beat Slytherin and win the House Cup.
Arthur found himself unable to sleep. Probably because of all the tension built up inside him. Though it was rough because he heard Neville sniffle into his pillow for what felt like hours. He also felt fear about how the rest of Gryffindor house would react to the loss of points.
The next day, Gryffindor passed the giant hourglass that recorded the house points and saw that fourty five points had been lost. At first, they thought it was a mistake, but then the story spread, somehow, that Arthur Pendergast, their hero of two Quidditch matches, had lost those points with two other first years for trying to keep Hagrid out of trouble. Of course, there was no mention of a dragon, thankfully.
So, despite the loss of points, all of Gryffindor felt like he and Chrys did the right thing, also knowing that Neville got mixed up in all of this. Both Ravenclaw and Hufflepuff also felt the same since the three houses collectively want to see Slytherin lose the House Cup. Of course, there was some resentment, because there was a chance that Slytherin could still win.
With Slytherin, they felt like they could win the House Cup, though there was evident concern. Draco glared at Arthur, seeing that he wasn't in too much trouble.
David, whose hand had finally healed, stood by their side and ended up explaining the truth to his brothers.
"Don't worry, compared to how many points Jack and Kevin lost, you'll be alright." He assured Arthur and Chrys.
Despite all of this, Arthur decided that he will never meddle in things that weren't his business from now on. The whole thing with Filch was his luck running out. So he'll now stop sneaking around and spying.
Quidditch, thankfully, still had its fun, though he occasionally had the odd Quaffle here and there thrown at him for losing the points. This was tolerable, though.
With Chrys and Neville, they suffered somewhat. Chrys, in particular, because she stopped drawing attention to herself in class, keeping her head down and working in silence, feeling somewhat embarrassed.
The exams were now no longer far away, which Arthur was glad about. All of the revision that he had to keep in his mind wasn't fun. He, David and Chrys would keep to themselves, working late into the night to remember the ingredients in complicated potions, learn charms and spells off by heart and memorise dates of magical discoveries and goblin rebellions….
It was a week before the exams were due that Arthur's resolve to not interfere with anything got put to the test. When walking back from the library on his own one afternoon, he heard someone whimpering from a classroom ahead of him. He then heard Quirrell's voice when he got closer.
"No, no, not again, please…" It was as though someone was threatening him. Arthur moved closer, not hearing anything else. Was Quirrell talking to himself?
"Alright, alright…." Quirrell then sobbed, again, not hearing anything else, meaning he was all alone.
Then Quirrell came out of the classroom in a hurry. He was also straightening his turban. He was also pale and looked like he was about to cry. He didn't seem to notice Arthur as he strode out of sight.
Once his footsteps disappeared, Arthur peered into the classroom to see that it was indeed empty. He remembered the whole thing with the hissing and growling from Quirrell's turban and a dark thought creeped into his head. That there was something attached to the back of his head and used the turban to hide it. It made sense as to why he was apprehensive to talk about it earlier in the school year.
This made him go back to the library where Chrys was testing David out on Astronomy. He told the two what he had heard and what he just theorised.
"Great. Just what we need, one of them to have some parasite or whatever telling them what to do." David groaned.
"Shouldn't we go tell Dumbledore all of this? That both Snape and Quirrell are after the Stone and are trying to find a way past Fluffy and whatever else is guarding the Stone?" Chrys then asked.
"The problem is that we have no proof. Plus, both of them would just deny it all. And it's common knowledge how much Snape is hated, Dumbledore will just think we're just making it up to get him sacked. And Filch is too friendly with Snape, so the more students that get expelled, the better. Plus we're not supposed to know about both the Philosopher's Stone and Fluffy, which will take a lot of explaining." Arthur argued back.
"Can't we just poke around-"
"No. I'm not going to take any more chances of getting caught and getting into more trouble." Arthur shot down David's idea as he pulled out a map of Jupiter and started to learn the names of its moons again.
The following morning, notes were delivered to Arthur, Chrys and Neville at the breakfast table. They all read the same thing:
Your detention will take place at eleven o'clock tonight. Meet Mr Filch in the Entrance Hall.
Prof. M. McGonagall
Arthur and Chrys were both silent, knowing they deserve this.
Once eleven o'clock rolled around, they said goodbye to David in the common room before making their way to the Entrance Hall with Neville. Filch was already there, as well as Draco. Arthur had forgotten that he also got detention and ended up losing some house points for Slytherin.
"Follow me. Filch said, lighting a lamp up and led them outside.
"I bet you'll think twice about breaking a school rule again, won't you, eh." He continued on, leering at the four of them. "Oh yes… hard work and pain are the best teachers if you ask me…. It's just a pity they let the old punishments die out… hang you by your wrists from the ceiling for a few days, I've got the chains still in my office, keep 'em well oiled in case they're ever needed…. Right, off we go, and don't think of running off, now, it'll be worse for you if you do."
They all marched across the dark grounds, Neville sniffing as they did so. Arthur was starting to think what their punishment was going to be. Based on how delighted Filch sounded, it must be something awful.
The moon was out, shining bright among clouds that scudded across, which kept throwing them into darkness. Just ahead, Arthur saw the lighted windows of Hagrid's hut.
"Is that you, Filch? Hurry up, I want ter get started." Hagrid shouted.
This made Arthur feel better, seeing that they'll be with Hagrid for detention. Of course, he was able to hide his relief from Filch.
"You lot will be going into the Forest with that oaf." Filch said, which made Neville moan and Draco to stop dead in his tracks.
"The Forest? We can't go in there at night, there's all sorts of things in there, werewolves, I heard." He said, sounding not as cool as he normally did.
The mention of werewolves made Neville clutch onto Arthur's robes and make a choking noise.
"That's your lookout, isn't it? Should've thought of them werewolves before you got in trouble, shouldn't you?" Filch said, his voice cracking with such glee that Arthur questioned why this guy is even the caretaker if he's this sadistic.
Hagrid came out, striding to them in the dark. Fang was at his heel as well. He carried his large crossbow and a quiver of arrows hanging over his shoulder.
"Abou' time. I bin waitin' fer half an hour already. Alright, Arthur, Chrys?" He then said as he reached them.
"I shouldn't be too friendly to them, Hagrid, they're here to be punished, after all." Filch coolly told him.
"That's why yer late, is it? Bin lecturin' them, eh? 'Snot your place ter do that. Yeh've done yer bit, I'll take over from here." Hagrid frowned at Filch.
"I'll be back at dawn for what's left of them." Filch replied nastily before turning and headed back to the castle, his lamp bobbing away in the darkness.
"I'm not going in that Forest." Draco said with panic in his voice, which pleased Arthur a lot.
"Yeh are if yeh want ter stay at Hogwarts. Yeh've done wrong an' now yeh've got ter pay fer it." Hagrid replied fiercely, putting Draco in his place.
"But this is servant stuff, it's not for students to do. I thought we'd be writing lines or something. If my father knew I was doing this, he'd-"
"-tell yer that's how it is at Hogwarts." Hagrid growled, cutting off Draco's complaining. "Writin' lines! What good's that ter anyone? Yeh'll do summat useful or yeh'll get out. If yeh think yer father'd rather you were expelled, then get back off ter the castle an' pack. Go on!"
Draco didn't move as he looked at Hagrid furiously before dropping his gaze. Seeing Draco be put in his place was satisfying.
"Right then, now, listen carefully, 'cause it's dangerous what we're gonna do tonight an' I don' want no one takin' risks. Follow me over here a moment." Hagrid then said, leading them to the very edge of the Forest. He held his lamp up high, pointing down a narrow, winding earth track that blended into the thick black trees.
A gentle breeze lifted their hair when they looked into the Forest.
"Look there, see that stuff shinin' on the ground? Silvery stuff? That's unicorn blood. There's a unicorn in there bin hurt badly by summat. This is the second time in a week. I found one dead last Wednesday. We're gonna try an' find the poor thing. We might have ter put it out of its misery." Hagrid explained, pointing at a small puddle of reflective, silvery thick liquid on the ground.
"And what if whatever hurt the unicorn finds us first?" Draco asked, now more unable to hide fear in his voice.
"There's nothin' that lives in the Forest that'll hurt yeh if yer with me or Fang. An' keep ter the path. Right, now, we're gonna split inter two parties an' follow the trail in diff'rent directions. There's blood all over the place, it must've bin staggerin' around since last night at least." Hagrid said.
"I want Fang." Draco said quickly, looking at Fang's long teeth.
"Alright, but I warn yeh, he's a coward." Hagrid replied, making Draco's eyes widen in worry, adding to Arthur's enjoyment of him being out of his comfort zone.
"So me, Arthur an' Chrys'll go one way an' Draco, Neville an' Fang'll go the other. Now, if any of us finds the unicorn, we'll send up green sparks, right? Get yer wands out an' practise now. That's it, an' if anyone gets in trouble, send up red sparks, an' we'll all come an' find yeh, so, be careful. Let's go."
Arthur found the Forest to possibly be scarier than the castle. It was all black and silent. A bit further in, they reached a fork in the earth path and as Arthur, Chrys and Hagrid took the path to the left, Draco, Neville and Fang took the one to the right.
They all walked in silence, eyes on the ground to see if there's more unicorn blood. Every once in a while, a ray of moonlight would crack through the branches and light a spot silver blue blood on fallen leaves.
"Could a werewolf be what's killing the unicorns in the Forest?" Arthur asked when seeing that Hagrid was looking really worried.
"Not fast enough. It's not easy ter catch a unicorn, they're powerful magic creatures. I never knew one ter be hurt before."
The three walked past a mossy tree stump. Here was where Arthur could hear running water, meaning a stream was nearby. They also still saw spots of unicorn blood here and there along the winding path.
"You alright, Chrys?" Hagrid whispered. "Don' worry, it can't've gone far if it's this badly hurt an' then we'll be able ter - GET BEHIND THAT TREE!" He seized both students, hoisting them off the path and behind a towering oak tree.
He then pulled out an arrow and fitted it into his crossbow before he raised it, ready to fire if needed. The three were dead silent, listening for any sound nearby. There seemed to be something slithering over dead leaves. Arthur thought that it sounded like a cloak. He started dreading who it might be. Then a few seconds later, the sound faded away, like whoever it was was walking away.
"I knew it. There's summat in here that shouldn' be." Hagrid murmured quietly.
"Right, follow me, but careful, now." He then said grimly.
They continued on more slowly than before, ears straining for even the faintest of sounds. Then suddenly, up ahead in a clearing, something moved.
"Who's there? Show yerself, I'm armed!" Hagrid called out.
An answer came when a figure entered the clearing. From the waist up, it looked like a man with red hair and a beard but below his waist was a horse's gleaming chestnut body with a long reddish tail. Both Arthur and Chrys' jaws dropped as they were looking right at a centaur.
"Oh, it's you, Ronan. How are yeh?" Hagrid said in relief, walking forward and shaking the centaur's hand.
"Good evening to you, Hagrid. Were you going to shoot me?" Ronan said, his voice sounding deep and sorrowful.
"Can't be too careful, Ronan. There's summat bad loose in this Forest. This is Arthur Pendergast an' Chrysanthemum Ranger, by the way. Students up at the school. An' this is Ronan, you two. He's a centaur."
"We've noticed." Chrys said in awe, thinking Ronan looked impressive for a centaur.
"Good evening. Students, are you? And do you learn much, up at the school?" Ronan then asked.
"Pretty much." Arthur replied.
"Good." Ronan sighed, flinging back his head and stared up at the sky.
"Mars is bright tonight." He then said.
"Yeah. Listen, I'm glad we've run inter yeh, Ronan, 'cause there's a unicorn bin hurt, you seen anythin'?" Hagrid said, at one point glancing up at the sky.
Ronan didn't answer him immediately. He simply stared without blinking upwards before sighing again.
"Always the innocent are the first victims. So it has been for ages past, so it is now."
"Yeah, but have yeh seen anythin', Ronan? Anythin' unusual?"
"Mars is bright tonight. Unusually bright." Hagrid started growing impatient.
"Yeah, but I was meanin' anythin' unusual a bit nearer home. So yeh haven't noticed anythin' strange?"
Once again, it took a while for Ronan to answer.
"The Forest hides many secrets." He eventually said. A movement in the trees behind him made Hagrid raise his crossbow again, though it turned out to be another centaur. This one had black hair, as well a black furred bottom half. He looked wilder in comparison to Ronan.
"Hullo, Bane. Alright?" Hagrid greeted him. Arthur had that feeling that Bane would be a bit more hostile than Ronan.
"Good evening, Hagrid, I hope you are well?"
"Well enough. Look, I've jus' bin askin' Ronan, you seen anythin' odd in here lately? Only there's a unicorn bin injured. Would yeh know anythin' about it?" Hagrid asked. Bane walked, standing next to Ronan and looked skywards
"Mars is bright tonight." He said. This made Hagrid grumpy.
"We've heard. Well, if either of you do see anythin', let me know, won't yeh? We'll be off, then."
Both Arthur and Chrys followed after him out of the clearing, looking over their shoulders at Ronan and Bane until their view was blocked by the trees.
"Are centaurs always like that?" Arthur asked.
"Never try an' get a straight answer out of a centaur. Ruddy stargazers. Not interested in anythin' closer'n the moon." Hagrid replied irritably.
"How many more are there?" Chrys then asked.
"Oh, a fair few…. Keep themselves to themselves mostly, but they're good enough about turnin' up if ever I want a word. They're deep, mind, centaurs… they know things… jus' don' let on much."
"So what we heard earlier wasn't a centaur?" Arthur asked, remembering that Ronan and Bane didn't wear cloaks.
"Nah, if yeh ask me, that was what's bin killin' the unicorns. Never heard anythin' like it before." Hagrid replied.
The three continued on through the dense Forest. Arthur would sometimes look over his shoulder, scared he'll see something right behind him. This was because he had that feeling they were being watched. He was grateful that Hagrid had a crossbow with him. When they had just passed a bend in the path, Chrys looked and grabbed Hagrid's arm.
"Hagrid, there's red sparks! They must be in trouble!" She said. Arthur looked and there were indeed red sparks in the air among the trees.
"You two wait here! Stay on the path, I'll come back for yeh!" Hagrid shouted before he crashed through the undergrowth.
The two stood, looking at each other, feeling scared as they eventually heard nothing but leaves rustling around them.
"Do you think they've been hurt?" Chrys asked quietly.
"I personally don't give a damn if Draco has, but if Neville's gotten hurt, it would be our fault he's even here." Arthur replied.
The following minutes dragged on, making their ears sharper than before. Arthur kept his eyes wide open, seeing if he could spot anything. For a split second, he swore that he saw the outline of a figure walking in the distance before blending into the darkness. This sent chills throughout his whole body and started getting more and more scared.
Eventually, loud crunching came towards them and Hagrid appeared with Draco, Neville and Fang alongside him. Hagrid was also fuming. It seemed that Draco decided to sneak up behind Neville and grab him for a joke. This made Neville panic and shoot up the sparks. Draco was starting to make Arthur furious. Now wasn't the time or place for jokes, especially because they're in the Forbidden Forest.
"We'll be lucky ter catch anythin' now, with the racket you two were makin'. Right, we changin' groups. Neville, you stay with me an' Chrys, Arthur, you go with Fang an' this idiot. I'm sorry, but he'll have a harder time frightenin' you, an' we've gotta get this done." Hagrid whispered to Arthur.
This made him roll his eyes in frustration. He didn't want to be with Draco but he had no choice.
And so he set off into the heart of the Forest with Draco and Fang. They had walked for roughly half an hour, getting deeper and deeper into the Forest until the path became nearly impossible to follow because of the trees getting thicker.
They've spotted splashes of unicorn blood on tree roots, making Arthur visualise the poor creature thrashing in pain. He then saw a clearing up ahead through tangled branches of an ancient oak tree.
"Wait." He then whispered, holding out his arm to stop Draco because he saw something bright white gleaming on the ground. Starting to feel dread, they inched their way closer.
They can see that it was the unicorn, and that it is also dead. Arthur couldn't comprehend how anyone would kill such a beautiful creature.
It was disturbing to see its long slender legs sticking out at odd angles and its mane being spread pearly white on the dark leaves.
Arthur only took one step when the slithering sound he heard before made him freeze on the spot. A bush on the edge of the clearing quivered before, out of the shadows, a hooded figure crawled across the ground like some stalking beast. Arthur was now more frozen in fear, remembering that moment he saw possibly the same figure from earlier, while Draco and Fang watched, transfixed. The figure reached the unicorn and then lowered its head over the animal's wound and started drinking its blood.
"AAAAAAAAAAARGH!" Draco screamed at the top of his lungs before bolting off with Fang, leaving Arthur on his own. The hooded figure looked up right at Arthur. Unicorn blood was dribbling down its front as it got to its feet and started coming at him.
Arthur felt a pain like he had never felt before. It was as though his head was on fire. He staggered backwards, trying to get away from the figure when hooves galloped from behind him and then something cleanly jumped over him and charged at the figure.
The pain in Arthur's head was so bad that he ended up falling to his knees. He also realised that the pain came from where his scar was. The pain also passed after a minute or two.
Looking up, he saw that the figure was gone and that a centaur was standing over him. This one wasn't Ronan or Bane. He looked younger and had both white blonde hair and a palomino body.
"Are you alright?" The centaur asked as he pulled Arthur to his feet.
"Yes… thank you. Just what the hell was that?" He asked. The centaur didn't answer. Arthur noticed his astonishingly blue eyes, looking like pale sapphires. He then looked at Arthur, his eyes lingering on the scar, which stood out on his forehead. A part of Arthur didn't mind the centaur looking at him.
"You are the Pendergast boy. You had better get back to Hagrid. The Forest is not safe at this time, especially for you. Can you ride? It will be quicker this way." The centaur said.
"My name is Firenze." He added as he lowered himself on his front legs for Arthur to get onto his back.
Then there was more galloping from the other side of the clearing. Ronan and Bane bursted through the trees, their flanks heaving and sweaty.
"Firenze! What are you doing? You have a human on your back! Have you no shame? Are you a common mule?" Bane thundered loudly.
"Do you realise who this is? This is the Pendergast boy. The quicker he leaves this Forest, the better." Firenze replied.
"What have you been telling him? Remember, Firenze, we are sworn not to set ourselves against the heavens. Have we not read what is to come in the movements of the planets?" Bane growled. Ronan pawed the ground in a nervous manner.
"I'm sure Firenze thought he was acting for the best." He said gloomily. Bane then kicked his back legs in anger. Arthur was getting nervous about all of this.
"For the best! What is that to do with us? Centaurs are concerned with what has been foretold! It is not our business to run around like donkeys after stray humans in our Forest!"
Firenze suddenly reared on his hind legs in anger, making Arthur wrap his arms around his chest and clinged on.
"Do you not see that unicorn? Do you not understand why it was killed? Or have the planets not let you in on that secret? I set myself against what is lurking in this Forest, Bane, yes, with humans alongside me if I must." Firenze bellowed back at him before he whisked around, Arthur still clinging on as best he could, and plunged off into the trees, leaving Ronan and Bane behind.
"Why did he get so angry? And what was that thing you saved me from?" Arthur asked, finding his voice again.
When Firenze slowed to a walk, he warned Arthur to keep his head low in case there's low hanging branches but he didn't answer his question.
Arthur suspected he didn't want to talk to him as they've made their way through the trees in silence for so long. They passed through a really dense patch of trees, though, when Firenze came to a halt.
"Arthur Pendergast, do you know what unicorn blood is used for?" Arthur found himself puzzled by the sudden and odd question.
"Not really. We only use the horn and tail hairs in Potions. And that their hairs are used for wand cores." He answered honestly.
"That is because it is a monstrous thing, to slay a unicorn. Only one who has nothing to lose, and everything to gain, would commit such a crime. The blood of a unicorn will keep you alive, even if you are an inch from death, but at a terrible price. You have slain something pure and defenceless to save yourself and you will have but a half life, a cursed life, from the moment the blood touches your lips." Firenze explained the severity of such an act.
"I'd have thought death would be better than a cursed life forever. Whoever would do that must be desperate." Arthur said, considering how there's one person he could think of that would be that desperate.
"It is, unless all you need is to stay alive long enough to drink something else, something that will bring you back to full strength and power. Something that will mean you can never die. Mr Pendergast, do you know what is hidden in the school at this very moment?" Firenze asked, making Arthur remember what the Philosopher's Stone can do.
"The Elixir of Life! The Philosopher's Stone can create it." He said.
"And can you think of nobody who has waited many years to return to power, who has clung to life, awaiting their chance?" Firenze then asked.
Arthur's heart sank as he remembered what McGonagall said when they first met: 'I think he's just too tired and too weak, hiding like a coward.'
"Voldemort." He whispered, seeing everything come together like a puzzle.
"Arthur, are you alright?"
Chrys came running towards them down the path with Hagrid puffing behind her.
"I'm okay. The unicorn's dead, Hagrid. It's in the clearing that way." Arthur said.
"This is where I leave you." Firenze murmured as Hagrid went off to examine the unicorn.
"You are safe now." Firenze then said as Arthur slid off his back.
"Good luck, Arthur Pendergast. The planets have been read wrongly before now, even by centaurs. I hope this is one of those times." He then said before turning and heading deep into the depths of the Forest.
David was fast asleep in the dim common room, waiting for them to return. When Arthur shook him awake, he rambled about something involving Merlin. But he instantly realised he was woken up and then Arthur went on to explain to him and Chrys about what happened to him in the Forest. He couldn't even sit down as he paced back and forth in front of the fire.
"It seems that either Snape or Quirrell want to get the Stone for Voldemort, who's waiting in the Forest. When Firenze saved me, it seemed like he shouldn't have because Bane was furious at him, saying that he interfered with what the planets said would happen. They must've shown that Voldemort is coming back and that he was to kill me." He said before he sat in an armchair.
"What will we do now?" David asked, feeling concern with all of this new information.
"Simple, wait for now until Snape or Quirrell attempt to steal the Stone and try to stop whoever it ends up being." Arthur replied.
"Hold on, it's common knowledge that Dumbledore is the only person that Voldemort ever feared. So as long as Dumbledore is around, Voldemort won't be able to lay his hands on you. Plus what the centaurs said sounds like fortune telling, which McGonagall says is a very imprecise branch of magic." Chrys added.
By the time they stopped talking, the sky had turned light. All of them went to bed exhausted, though the surprises didn't end.
Arthur was shocked to see his Invisibility Cloak folded neatly on his bed when he pulled back his sheets. The Cloak also had a note pinned to it that read:
Just in case.
Now if any of you remember in the book, McGonagall was so severe with how many points she took off Gryffindor because she assumed that Harry made up a scheme to get Draco into trouble as he and Hermione didn't say anything. Whereas here, because Arthur told her the truth, she wasn't as severe and yet still had to punish them.