Year Six of my Doctor Who/Harry Potter crossovers. This story is a little different to the others, but hopefully you'll still enjoy it.
In any case, a more light-hearted start. As you can probably tell, it won't last; there are still several storylines yet to be resolved, such as the masked woman, and the ghost.
Also, if you haven't already, I'd suggest reading Changes. It's the first of this series, and as we're nearing the end, there will be several references to the start that might not make sense otherwise.

"2134!" the Doctor announced, with a grin like a showman, as he swung the TARDIS door wide open. A frown; "Definitely better than a boring old pirate ship."

"You're just jealous that I got the coat," Amy laughed, following the Time Lord out the box. "So, Earth still, huh?"

"Yep," the Doctor grinned, looking around. He frowned; "Cardiff again? Why here old girl?" he rested on the door, gently caressing the blue. "Well, you know best."

For a moment, Amy was sure that she heard a distant, almost smug, groan deep inside the time machine.

Amy and Rory followed the Doctor out into the crowd, wandering around and mingling in the futuristic environment. It was somehow more alien than a great many planets; still recognizably human, yet different enough to be unsettling.

It seemed that they were in some kind of shopping district. They walked on what looked like a road, yet was covered with people; the actual transport seemed to be on monorails above them. Either side of the path stood rows of booths, all with people peering out. Occasionally, a passer-by hopped inside.

"Most buying and selling stuff is done online," the Doctor narrated as they walked through the city. "Only reason these shops are here is for nostalgia. And for things where the buyer actually has to be present. Still, can't say no! I love a little shop," he frowned; "Though this was the dark era for those, until the little shop revolution of 2189."

They arrived at a split in the street; one route heading into a larger marketplace, the other leading into a metropolis; the residential block, it would seem.

Grinning, the Doctor lead them towards the marketplace, looking around at all the signs, statues and merchandise with a childlike amusement; as if he'd never seen such things before.

They passed a skyscraper; it reached up, until it touched the monorail system high above the streets.

"You're sure this is Cardiff?" Rory said, frowning

"No," the Doctor admitted. "Scanner's a little fuzzy; small temporal disturbance. We're definitely somewhere on Earth though," he frowned, "Well, in the Milky Way. Probably."

"Do you ever know where we are?" Amy rolled her eyes

"Where's the fun in that?" the Doctor flashed a contagious grin, before running off towards a booth-shop that appeared to be selling a cross between a corkscrew and a cactus.

The Ponds hesitated, waiting for the Doctor; just once, they'd like to not be completely separated. Quietly, they moved to the side of the path, nearer to the booth-shop.

"Hands?" the booth-keeper leant out; a gnarled old man, "Want any hands?"

"We uh-" Rory frowned, looking at the vendor.

Visible along the back wall of the booth-shop were actual, mechanical hands. Some gold, some silver, some humanoid, some not. One particularly bizarre one was hot pink, and had no fingers; instead, there was what looked like a light bulb in the palm. Around it were more conventional, if that word could be applied, hands; one was a fairly accurate replica of normal skin, save for the fact it was the colour of the sky, with no nails.

The booth-keeper lifted an arm, to gesture at his wares. The Ponds glimpsed the end of his wrist; it joined smoothly with one of those constructed hands; a red one, the index finger with a small laser light inbuilt, pointing directly at one of the unsettling prosthetics on the back wall.

"Um, ah-" Rory stuttered, unsure of quite how to respond to the offer without being rude

"No thanks," Amy cut in, "We've got our own hands."

"Hm," the booth-keeper peered forwards, over the counter to see their hands, "Still on the old flesh-and-blood? I'm licensed to perform the op. Come on in, we can get you fitted."

"No thanks," Amy repeated, sidling, mildly rudely, away from the salesman and his disturbing wares. Rory, gratefully, followed, instinctively massaging his own hands.

Unsettled, the couple waited again towards the sides of the path, but further away from the booths, until the Doctor came back. The Time Lord now wore a bizarre contraption on his head.

Imagine a corkscrew. Then give it two cactus arms, add a few prickles, a tassel, and take away the screw itself. It wouldn't quite do justice to the weirdness of the new hat, but it was as close as any sane mind would want to come to comprehending the disaster.

"I think I preferred the fez," Amy murmured faintly.

"Oy! Don't knock the hats," the Doctor patted the…thing. "So, what were you two up to, see anything you like? I hear they make really nice pizza this year."

"Doctor," Rory said, tentative. "I think someone was trying to sell us robotic hands."

"Oh, a hand merchant," the Doctor grinned. "Almost forgot those! See anything you like? Met a rather nice man a while ago, replaced his hands with feet, and his feet with hands. And his head-" the Time Lord paused, just in tiem for Amy to interrupt.

"Hang on, what?"

"Didn't I say?" the Doctor frowned, "Sorry. It's all the rage for this decade, people lose their hands, and get mechanical replacements, for style."
"They chop of their hands?" Rory said, disbelieving. "That's-"

"Oh, humans," the Doctor rolled his eyes. "It's really not that different to your time; by then they're already jabbing their way through ears, mouths, eyebrows," he winced, "Other places. So-"

The Doctor hesitated mid-rant, eyes focused on something behind the Ponds. Confused, Amy and Rory followed his gaze.

A pale blonde walked up to them; she was about fifteen, and dressed in mystical black robes. The girl walked past them, stopping only to nod once, distracted, giving no sign of any major concern.

"Hello Doctor, hello Amy, hello Rory," she smiled, before walking onwards.

A pause; the trio of time travellers looked at each other.

"I- um, don't mean to be stupid, but was that-" Rory began

"Well don't say anything," the Doctor interrupted, pleased with himself for being so helpful.

"Was that Luna?" Amy said, taking up her husband's words.

"Yep," the Doctor nodded, "Luna Lovegood, fifth year at Hogwarts about, ooh, over a century ago." He frowned. "Hang on," the Time Lord span around.

Seconds later, the trio were running after the student, as she wandered through the street; casually pacing in a time over a century beyond her own. They caught up with the blonde at a fork in the road.

"Hello Luna," the Doctor grinned, hopping up to the student. "So, do you know where you are?"

"Probably the future," Luna observed, detached. "It doesn't look much like Hogwarts, does it?"

"Not really," the Doctor fell into stride next to the Ravenclaw, "I don't suppose you know how you got here?"

"No," Luna sighed. "I expect it's just a Dual-Tailed-Moroff. They can send people through time, you know."

"Really?" the Doctor seemed interested. "Well, do you want to get back?"

"Ok," Luna frowned, "Have you found the Moroff?"

"Something like that," the Time Lord flashed a grin.

Luna Lovegood followed the trio of time travellers, back through the wide streets, keeping away from the booths, until they reached the familiar, comforting shape of a blue police box. The Doctor clicked his fingers; slowly, the doors swung open.

Dreamily, Luna wandered into the TARDIS; she didn't look around, didn't even gasp as she beheld the impossible interior dimensions. Quietly, keeping to herself, she walked up to the central console.

Disappointed somewhat at the lack of a reaction, the Doctor leapt around the central console, flourishing madly. The TARDIS began to wheeze and groan.

"Right," the Doctor jumped on the spot, "Which date did you come from?"

"October 5th," Luna said. She frowned, looking around at the TARDIS, for the first time, before continuing; "1996."

"Thank you," the Doctor clapped his hands, and hit one more button.

The time machine juddered to a halt.

Broadly grinning, the Doctor sprinted up to the doors, and leapt out. A split second later, he grabbed hold of the hinge, and pulled himself back in. Outside was empty space.

"Yeah, that sometimes happens," he mumbled, "Orbital fluctuations. We're on the-" he stopped, staring out the door. The Earth, whirling in its orbit around the Sun, was coming straight for them.

"This is what happens if you arrive a few minutes early," the Doctor rolled his eyes, muttering to himself. "Temporal waves; vortex is a little choppy. One sec."

As the TARDIS started to shake, entering the atmosphere of the oncoming planet, the Doctor yanked a lever down. A groaning; and the TARDIS materialized once more.

Tentative this time, the Doctor peered out the door, one hand resting on the thing he wore on his head (Amy refused to grace it with the title 'hat').

They were in Hogwarts; just with a small problem. They were precariously balanced on the top of one of the towers; leaving them with an awe-inspiring view combined with a staggering drop.

"A little turbulence," the Doctor admitted, still staring out the door. "We're close though! Within a few hours, and a few metres. On the grand scale of things…" his voice trailed off.

He span around, looking at the trio of humans; Luna, Amy and Rory. A spark glinted in his eyes, and he grinned. Amy knew that look; her stomach plummeted.

"Back in a sec," he grinned, before taking a short jump out the door.

"Does he have a broomstick?" Luna remarked conversationally. "Or maybe a Fizzing Whiz bee."

"He'd better," Amy muttered.

Outside the TARDIS, the Time Lord was desperately clinging onto a window ledge atop the huge tower, gratefully still in possession of his cactus/corkscrew 'hat'. Straining, he lifted his head up, staring into the window.

Dumbledore looked down at him; bemused.

Several minutes later, the Doctor had been pulled into the Office, and a quick spell had levitated the TARDIS to a courtyard far below. The Time Lord stayed with Dumbledore, in the headmaster's office, as they waited for the trio to climb up to them.

"You ok?" the Doctor struck up a chat.

"As well as can be expected," the headmaster lifted up a withered hand, caught in the thrall of a ring.

"Horcrux," the Doctor murmured, "No, forget I said that. You find it out later. So, anyone complained about the last two years?"

"Fortunately, your friend Rory was a truly impressive replacement while I was…indisposed," Dumbledore nodded thanks; "I trust the Voice will no longer prey upon the castle?"

"Nope, tricky little thing's in here," the Doctor tapped his forehead. "Currently listening to part of me give awful fashion advice," he scratched his cactus/corkscrew hat. "So, everything fine here?"

"Doctor," Albus met the Doctor's eyes, changing the subject in resolute tones, "I doubt you landed on my roof for purely social reasons."

"No, well, kinda. Met Luna in the twenty second century, felt like she should be returned," the Doctor shrugged. "She's back now, even if time's been a little wrecked around this year. Quite hard to land properly."

"Ah," Dumbledore paused, "Do you know how she happened to come into the later century?"

"Well…no," the Doctor frowned. "Have you heard of the Dual-Tailed-Moroff? That might be to blame."

"It would be too much to ask, for a genuine answer," the headmaster sighed. "I assume you will once more be staying for the year?"

"Yeah…sorry," the Doctor gave a guilty smile.

On their way through the corridors, outside the Office, Amy Rory and Luna wandered past relatively sparsely packed groups of students. They seemed somehow more withdrawn, less active than such students generally were.

Not surprising; given recent events. Voldemort's confirmed return, and the death of one of the students, Ginny. One thing that few students wanted to know, was their own mortality: and with the untimely demise of Ginny, that fact was all too clear.

"Ooh, Draco," Amy said suddenly, thinking. "Give me a moment," the redhead walked away from Rory and Luna, gesturing for them to continue. Her words could just be heard, before they walked too far away; "Just who I wanted to see…"

Amy caught up with the other two, a little while later; just outside the gargoyle that lead to Dumbledore's Office. As they arrived, the statue lowered, bringing Dumbledore and the Doctor with it.

The Time Lord took a long stride forwards, grinning. He seemed about to speak, when another cry rang out:

"Reducto!"

A jet of light; the cactus/corkscrew on the Doctor's head fell away, obliterated to dust, fragments of the thing touching the stone ground.

The Doctor patted his own unruly hair, aghast at the loss of the recently acquired headgear. He looked around; eyes focusing on a distant, brief blur of blonde in the distance.

"Thank you Draco," Amy muttered to herself, smiling.