Later:

  Barnaby woke up!

  I was in my dormitory, alone, when I heard a voice coming from under the bed. It gave me a shock, at first, but when I remembered the portrait was under there, I pulled it out.

  "Th're wast a spider,"Barnaby James was grumbling.

  "Good, you're awake!"I said.

  "Wh're didst wend?"Barnaby went on.

  I think he was asking where it went (the spider).

  "I can't see any spiders now,"I began...

  But then I noticed a large one creeping over the top corner of the portrait as I was holding it.

  I threw it across the room! The portrait bounced off the wall, Barnaby yelling as it did, and the spider fell onto the floor and ran towards me! I jumped onto a chair, and the spider ran under Priscilla Bulstrode's bed.

  "What is happening?"Barnaby was yelling.

  I got up, retrieved the portrait, and sat at the other side of the dormitory, anxiously keeping Priscilla's bed in view, in case the enormous arachnid should make a reappearance.

  "It's alright,"I thought,"I'll go and get Oliver."

  "Please stay awake,"I said to Barnaby,"I'm going to get my snake to eat that spider."

  "A snake?"Barnaby responded, looking bewildered.

  I went to the Transfiguration Courtyard. Oliver has a nest there, under a bench, under a tree. Fortunately he was in his nest, and not off on one of his 'travels'.

  "Could you come with me to eat a spider?"I asked.

  "Depends on if it's a nice, big one,"Oliver replied,"I'm not going down into those horrible dungeons to eat a tiny little crumb of a thing, like last time!"

  "It's a huge one!"I insisted,"and there might be more where that came from."

  "Nice and big and juicy?"Oliver asked.

  "Yes, very juicy,"I said, shuddering,"come on."

  Oliver hid under my cloak. When I returned to my dormitory, Oliver did find the spider, but Barnaby had fallen back to sleep. I tried to wake him, but it was no use.

  I was so mad at that spider! Now I'd missed my chance to ask him about Spinner!

  Oliver found three more spiders, while he was at it. That, at least, cheered me up a little bit.

  In frustration, I'd thrown the portrait onto the floor and slumped onto my bed, staring up at the top of it (it's a four-poster) in annoyance. Then, after a few moments, I heard a voice.

  "Th're wast a snake!"

  I sat up and looked down. Oliver was next to the portrait. Barnaby was awake, and looking around anxiously.

  I picked up the portrait.

  "Are you afraid of snakes?"I asked.

  "Dreadful creatures,"Barnaby mumbled.

  "Well, he ate the spider,"I said.

  Barnaby shuddered,"I cannot abide..."he began, then yawned.

  "Don't you dare!"I said.

  "What?"he responded.

  "I want to ask you about Spinner,"I said,"who was he?"

  "Spinner wast a witch,"he yawned, then added,"Mary Spinner."

  And then, well, you can guess what he did next! The only sounds to be heard from his portrait were infuriating snores! I threw it under the bed and gave up!

  At this rate, we'll have solved the mystery by ourselves before Barnaby is able to tell us what happened.

  The narrative has been illicitly obtained; should you discover it on Amazon, report the violation.

  I went to return Oliver to his nest, but as I descended the stairs to the Common Room, I walked into a commotion.

  Llywellyn had gotten into a heated argument with some 3rd Years, and one of them responded by hitting him with a jinx that sent him whirling up into the ceiling. He was spinning around constantly, shrieking all the while! I didn't know the counter spell.

  "Get him down!"I shouted to the giggling 3rd Years.

  "No! He can stay up there!"a boy with spiky, ginger hair (one of them) retorted.

  All of a sudden, there was a dreadful retching sound, and then the ginger boy (Gregory Harp) was covered in vomit that had come from the ceiling, and more precisely, Llywellyn, who had gotten sick from the spinning around. It may or may not have been aimed on purpose.

  There was an uproar!

  "See! That's what happens when you spin people around in the air!"I said,"get him down now, or he'll be sick again!"

  Soon Llywellyn was back on the ground, sitting on the floor, looking very pale and confused. Gregory had gone with the other boy (Nathaniel Highwater) to remove the vomit from his person; and a girl with short, curly hair (Cecilia Forrester) remained. She was marching up towards Llywellyn and was about to hex him, but I disarmed her with 'Expelliarmus'.

  "Stop all of this at once!"I ordered,"he can't even defend himself."

  "Stupid Muggle,"Cecilia muttered,"well, we will get him back!"

  "He got you back, more like!"I said,"who hexed him in the first place?"

  "You didn't hear what he said!"Cecilia objected.

  "It doesn't matter what he says,"I said,"he can say what he likes, and so can you!"

  "He doesn't believe in magic,"Cecilia went on.

  "So what?"I said,"what does it matter when you use it all the time? You know it's real. He doesn't have to."

  "I bet you believe in magic now, don't you, Muggle!?"Cecilia yelled at Llywellyn, who was now lying on the floor, looking dazed.

  I went to help him up.

  "Come on, Muggle! Look at me and tell me that wasn't magic?"Cecilia insisted.

  "Some kind of gravitational force manipulation,"Llywellyn was muttering,"I'll have to find the machine that powers it. Operated by those sticks... voice activated remote controls..."

  "What Muggle nonsense!"Cecilia hissed.

  That was when I noticed Oliver was gone. He wasn't hiding in my cloak. He'd gone off somewhere. He must have been frightened away by the commotion.

  The common room was mostly empty by this point (Cecilia had gone while I was looking for Oliver).

  I decided to risk calling to him, quietly (Llywellyn doesn't know about Parcel tongue). I heard an answer and followed it. It seemed to be coming from the waterfall that pours down at the bottom of the stairs.

  I listened, closely, it was coming from... the drain...

  "Oliver!"I whispered.

  "I'm stuck!"Oliver replied.

  "How did you get down there?"I asked.

  "I fell down, looking for a place to hide,"Oliver responded, miserably,"can anyone get me out? There's an interesting thing down here, by the way."

  There's a small sort of pond basin in front of the drain. It has fake lillies in it. It's a fancy drain, above it, it's guarded by a stone beast with tusks and sharp teeth.

  Unfortunately, I had to venture into this pond of shallow water to get close enough to the drain. I couldn't see Oliver down there, even when I cast 'Lumos', it was too dark and shadowed.

  I drew out my wand,"Accio snake!"

  Oliver whacked into the metal grate of the drain.

  "Ow!"he objected.

  I tried getting Oliver through the grate, but it was difficult and he fell back down.

  "Please don't do that again!"Oliver begged,"I'd rather stay down here!"

  "Accio grate!"I said, this time.

  Surprisingly, the grate came away easily, and I was able to look down into the space below.

  There was a small chamber there, beneath the floor of the common room. I still couldn't see Oliver, so I decided to climb down.

  "What are you doing?"I suddenly heard Llywellyn's voice behind me.

  "I'm looking for something I lost,"I said,"go away, please!"

  "What did you lose? I can help!"Llywellyn persisted.

  That didn't work.

  "Well, are you afraid of snakes?"I asked.

  "No! I like snakes!"Llywellyn answered, eagerly.

  Well, that hadn't worked!

  "I'd rather you didn't come down here,"I said,"it might be dangerous. Just - go and read a book or something."

  "Is it a secret passage?"Llywellyn continued.

  I decided to ignore him and carry on with retrieving Oliver.

  It was as you would expect a drain to be, grimy and dingy and smelling, well, like you would expect. Sort of damp and mouldy.

  I cast Lumos and saw a place where the water was draining out further down, and when I crouched down, I could see that there was a sort of ridge above the flow of water, like a natural shelf space. There, I could also see Oliver, and - something else.

  A metallic green ball. It was making the same humming sound that I have been hearing on and off...

  "Is that a...?"I was wondering,"...is that a Sivril?"

  I got Oliver out first, and then reached down for the green ball, which I concealed within my robes, before climbing back up into the common room and returning the grate to its place.

  "I'm bruised all over!"Oliver mumbled,"I deserve ten newts for this! Ten!"

  "It's difficult for me to get newts now that I can't leave the castle grounds, but I'll try my best,"I answered.

  "What's that noise?"Llywellyn asked, looking frightened.

  I wondered if he could hear the humming sound too.

  "Do you hear it?"I asked.

  "I don't hear it now,"he answered,"that horrible, whispery sound, it gave me the creeps!"

  I realised he was talking about my conversation with Oliver...

  "It's nothing, don't worry about it,"I said, not sure what else to say.

  "Did you find what you was looking for?"Llywellyn asked.

  I showed him Oliver.

  "Can I hold him? Please!"he begged.

  "Don't!"Oliver hissed at me.

  "He doesn't like being held by strangers,"I said.

  "Can I pet him?"Llywellyn persisted.

  "Ugh,"Oliver said,"alright, he can. Tell him I like newts."

  Llywellyn put out his hand, and Oliver slithered into his arms.

  "He - uh - he likes newts,"I said,"if you could find one for him, he would appreciate it very much."

  "Of course I will!"Llywellyn answered, enthusiastically,"I know where to find newts! I've seen some already, by the Black Lake! I'll get him some later."

  "That'll be a nice change from spiders,"Oliver mumbled.

  "I need to return him to his home now,"I said, taking Oliver back,"you can come and see me when you've found him a newt."

  "Of course,"Llywellyn responded.

  I went to put Oliver back in his nest in the Transfiguration Courtyard.