I finished this chapter quite a while ago, but my internet was broken for the majority of today, so I'm only just getting around to uploading it.
Hope you enjoy the next part! Still introducing a fair few bits.

Also: if you enjoy this, check out Striders-Girl89's story 'The Tales of Bella Lumic'. It helped inspire some of this story, and it's great!
And back to the story:

"Thanks for all you're doing," the Doctor said, legs swinging over the edge of a table.

"It is no trouble, Doctor," Dumbledore replied.

They were in his office; the Headmaster by his desk, the Doctor closer to the entrance. The TARDIS stood to the side, out the way.

"I mean, I know I'm a pain and all, lots of people say so. Actually, I say so sometimes, especially when I talk to myself. Which is quite a bad habit, I keep telling myself not to do it, but I never listen," the Doctor shook his head and sighed, "Anyway, thanks. I mean it."

"What could I do if I did not accept your aid?" Dumbledore looked at the Time Lord, smiling, "You speak of things that I would not have the faintest clue how to deal with."
"Oh, neither do I most of the time." The Doctor grinned.

He paused, looking around the room.

It fascinated him how many little gimmicks there were. The Doctor had accumulated and invented a great deal of similar gizmos himself, but he was several centuries old: Dumbledore had gathered all this in a human lifetime.

There were things resembling microscopes, gems, cutlery and, the Doctor noted with glee; the deluminator. Giddily grinning, he picked it up in one hand, and flicked it. The light in the room, just next to him, was promptly extinguished.

"Always wanted to do that," he muttered, before flicking the light back on and putting the device down, "So," he looked back at Dumbledore, "Any odd news from the Wizarding World?"

"A rather eccentric man visited Hogwarts School," Dumbledore replied, amused

"Really?" the Doctor brightened, before slumping: "Wait, that was about me."

Dumbledore's eyes twinkled.

"There is more," Dumbledore continued, "They say something happened at Ollivander's wand shop, and you already know of the centaur."

"Right," the Doctor clapped his hands together, "We'll start there."

O

Harry wandered down the corridor, pacing, bored. He'd just survived his first lesson with the new Defence Against the Dark Arts teacher: Gilderoy Lockhart, arguably worse than Quirrell, and Quirrell had Voldemort in the back of his head!

Now he was on his way to a detention he'd been given after his unorthodox entry to Hogwarts, via flying car. Apparently Lockhart insisted but some new person, the 'Doctor', had been given the opportunity instead. A fair few students said they'd talk to him after; they hadn't really been told much about why the Doctor was there.

"Boy!" a deep, rumbling voice caught his attention. Harry turned, to see a strange creature.

It was a centaur, unmistakably. Its lower body was formed of shaggy, matted brown horse hair, over a strangely thin frame. Its back hooves appeared to drag a little. Its front however wasn't so much menacing, as wild; strong, visible muscles going down dark flesh, thick fingers, each stained by dirt. Its face glared down, harsh eyes peering through coarse, unkempt strands of hair.

"Yes, um-" Harry paused; he'd had an experience with centaurs last year. He knew not to act too superior, but also knew not to be too cowardly. He was a little shocked at seeing the being simply standing in the corridor.

"I am Lellorian. We will speak again."

The so-named Lellorian observed the student for a few more seconds, before quickly turning and galloping off. His hooves clopped on the stone floor.

Confused, Harry took another step down the corridor, away from the centaur, before encountering the Doctor.

"Hello!" the man knelt down until his face was level with Harry's, "You're Harry aren't you? I'm the Doctor!" he stood up, about to lead Harry into his room before, almost incidentally, turning around and saying; "Oh, and I probably shouldn't say this, but you might want to start talking to Ron's sister. You know, Ginny. Or Draco actually, he was a popular choice."

With that remark, accompanied by a frown, the Doctor walked into the spare classroom.

Harry followed, looking around, surprised at the state of the room. Apparently the Doctor had converted it into his own office; there were two, comfy, cushioned chairs facing each other in the centre, with all the tables pressed against the walls of the room, except for on which was to the side of the two chairs; not between them. All the side tables were littered with gadgetry and confusing,, chaotic creations; coat hangers, chairs, sticks, and often general indistinct items, all blended into one bizarre mess.

"Come on Harry!" the doctor sat down on the far seat. Tentatively, Harry followed and sat on the other. "So," the Doctor continued, pausing, before leaning forwards, serious, "Have you seen a fez anywhere around here?"

"No," Harry blinked.

"Oh," the Doctor looked disappointed. "Too bad. Um, so, anything weird at all?"

Harry paused; thinking of the strange thing he'd seen when flying in the car the grey in the Forbidden Forest. Then he thought of Lellorian; the centaur.

"No," he said.

The Doctor slumped back, disappointed. A few seconds ticked by, before Harry couldn't resist asking:

"Um, sorry sir, I don't want to be rude, but what do you actually do?"

"Well," the Doctor paused, "Travel in a box, run a lot, get into trouble, and wear bow ties," he looked at Harry's expression, "What? Bow ties are cool. Oh!" the Doctor slapped himself, "You mean, what am I doing here? Well, investigating really. Quite a bit actually, but you won't want to know all the details. Besides, I'm giving you detention; be glad of that! It's me," the Doctor leant forwards, solemn, "Or Lockhart. You've got to admit, I'm better than him."

At that, Harry couldn't help but to agree.

O

Rory nervously walked out into the corridor; the Doctor had told him what he had to do, and how important it was.

His job, for now, was to keep time preserved. As the year ticked by, the changes caused by the premature death of the diary would grow and swell; Rory had to keep things roughly in one piece.

He had with him, a pot of red paint, and a brush. Harry would be coming this way after he'd finished at Nearly Headless Nick's Death-Day party; which, book wise, was the right time. The rest of the school should be at the Feast.

Rory double checked the edition of the book he'd taken to carrying with him, though hadn't yet read. The words were there.

Breathing heavily, he began to paint on the wall: THE CHAMBER OF SECRETS HAS BEEN OPENED. ENEMIES OF THE HEIR BEWARE.

The words the Diary had caused to be painted, now painted by his hand; preserving the timeline, and the reactions of the staff. Well, as best they could. They couldn't exactly go around stunning the Basilisk victims.

As Rory backed away from his completed work, he reflected soon; they didn't need to. In the corridor to his side, which he hadn't noticed before, a girl was laying, sprawled on the floor. At first he felt afraid; that she'd seen what he'd done. But then, as he approached, he noticed that she'd been petrified.

Rory backed away; now at a run. He had to put the paint away, wash the splatters off his guilty hands, before he could do anything.

O

"Hestia!" McGonagall let out a hoarse whisper upon seeing the student; she was Slytherin, and yet now lay on the cold stone floor, petrified by means only available to the Basilisk. The Basilisk who belonged to the Founder of Slytherin and as such, shouldn't harm Slytherin students at all.

Rory now stood with a small crowd on teachers, hands still a little damp from when he'd hastily washed them. He looked around, sparing a sympathetic glance for Harry, Ron and Hermione who were caught in the middle of it.

What he was really looking for, however, was something reflective, something to have weakened the glare of the Basilisk. It didn't take him long; the floor was covered in water.

"No…" a weak whisper came from one of the huddles of students, all massing around the point. Rory looked over; it was another Slytherin girl. She bore an uncanny resemblance to the one McGonagall had identified as Hestia.

"That's Flora," the Doctor's voice carried over, whispering into Rory's ear. The man didn't turn round, though he still paid attention; "Hestia's twin. They were only ever in the film version. I looked her up before I got here."

Rory nodded, glad to hear the new information, but a little scared by it. His heart ached in sympathy for Flora: it hurt to lose someone close. He knew.

O

Amy sighed wistfully, looking over the messy room. She'd been sent here by the doctor, to investigate apparently. He'd even lent her a magnifying glass.

Shrugging, the redhead paced into the shop; it was Ollivander's, reportedly ransacked quite recently.

"Heya- ah, Ollie!" she called into the shop.

A man, so pale he was almost a ghost, seemed to almost glide out of the back of the shop; "Yes? Are you here for a wand?"

"Ah, no," Amy shook her head after a second's temptation, "I'm here about the theft. Someone broke into your shop, right?"

"Ah, yes," Ollivander nodded. "A strange case. A crate of wands was stolen from me, but they were nothing special. All rowan, thirteen ten inches, fourteen eleven inches, eight ten and-"

"Alright," Amy interrupted quickly, before he could go through the entire inventory. "So, lots of wands were stolen. Can you think why?"

"I am afraid not," Ollivander seemed genuinely puzzled, "They would be of no use to a stranger. The wand chooses the wizard, after all."

O

The Doctor paced down the hall; his detention with Harry had just finished. Quite fun actually; ok, the timelines strictly shouldn't allow it, but for one, he needed to talk to as many people as possible, the eyes and ears of Hogwarts to be looking out for the cause of the end of Earth, and secondly, Lockhart was just a pain.

The Time Lord paused after a few steps, peering down at the floor. He knelt down, rubbing two fingers along the stone.

It was barely there, a trace admittedly, but distinctly visible. Marks; breathing audibly, the Doctor ran his hand over the mud, specks of dirt. Hooves.

Didn't Dumbledore mention a centaur seen in Hogwarts? The Doctor wasn't an expert, but from what he'd come to believe of the creatures from the books. They were a proud race; and most disliked humans. Why would any bother to come into the school?

Still, a centaur had been here. Or an actual horse, come to think of it. But wasn't a centaur more likely? Then again, he'd seen a horse on a spaceship once. As well as France. Still, he knew there was a centaur wandering around; until he'd met a horse, and named it Arthur, he'd stick with being suspicious of the centaur.

He was about to continue on, to Dumbledore's office for a chat with the headmaster, when his eye caught something else. A stream of spiders were steadily scuttling down the side of the corridor. A chaotic march, afraid.

"Spiders flee from it," the Doctor murmured to himself, quoting the book.

It looked like the Basilisk was still on the loose, slithering around Hogwarts despite the death of the Diary.

And that gave him another thing to add to his list.

The Doctor turned around, away from the footprints and Dumbledore's Office, and started towards Myrtle's bathroom. The entrance to the Chamber of Secrets.

O

Two eyes, beneath pale blonde hair, watched from an empty room. As Harry walked away from his detention, the boy, the watcher, walked out to him.

"Heya Potter!" the student said with a half-sneer

"What'd you want Malfoy?" Harry didn't turn to face the newcomer; Draco

"Who says I want anything from you? But I saw you talking to Lellorian."

"So?" Harry shot back defensively

"Oh, come on Potter, even you should no centaurs don't just wander around schools."

"Right," Harry rolled his eyes, making sure Draco knew he was being sarcastic, "How do you even know his name?"

"`Cos he gave up on me. Why'd you think he's talking to you? Not like you're anyone's first choice."

Harry didn't reply, just walking straight down the corridor

"Just look Potter, you know I don't like you," Draco continued, "Just, don't trust Lellorian. He's going to get you to steal something for him. Don't."

With that, the Slytherin student turned and walked the opposite way to Harry, straight away from him.

The black haired Gryffindor frowned, looking at the unlikely-helper. Don't trust Lellorian? Harry hadn't in the first place, but now he was even more inclined not to; especially if even Draco had refused.

Was it really trying to steal something, as Draco said? If so, what?

O

The Doctor stood on the wet floor, in the girls' bathroom. In front of him, the sinks stood; the entrance to the Chamber. Something must've been here.

A girlish wail sounded, and something shot up out of one of the cubicles. Moaning Myrtle shot into the Time Lord's sight. She drifted sideways, frowning, and leaning closer, leering at the alien.

"This is the girl's bathroom," she said, "Boys aren't allowed."

"Ok, I'll bear that in mind," the Doctor darted around the side of the ghost, shivering as she passed straight through him

"You're a boy," Myrtle said with a slight lisp

"Not my fault," the Doctor knelt down, looking around the circle of sinks as the ghost followed him.

"Still means you can't come in."

"Right," the Doctor replied, distracted as he ran his sonic screwdriver over the sink, illuminating the room in a small green glow, "So, anyway. Even though I'm not technically allowed in, I still am, so I must have some kind of permission, right?" the Doctor paused, putting his screwdriver away and flashing his psychic paper to Myrtle: "This!"

"Ooh, you're investigating," Myrtle adorned the word with a sceptical giggle;" Why'd that lead you to the girls' bathroom?"

"Look, Myrtle," the Doctor stood up, facing the ghost in her eyes. He rested his hands on the air, just over her shoulders; "Believe me; you died here, yellow eyes coming from the sinks. That's the reason I'm here."

With that, the Doctor span around and buzzed the sonic screwdriver at the sinks. A small machine he'd noticed, hooked over the back of the tap with a snake on, was activated; it lit up for a brief second and then, as surely as if he'd commanded in it parseltongue, the entrance to the Chamber of Secrets opened.
"Oh," Myrtle kicked back a few steps, as if swimming, "You're here for that? Go find a centaur, he kept barging in here too. Nearly as rude as you."

The Doctor frowned, turning. Centaur? Like Dumbledore had mentioned.

He turned and sealed the Chamber with a buzz from his sonic; first thing's first. That centaur was getting everywhere. He needed to find it.