~Lucifer in Starlight~

Summary: The crew of the USS Enterprise is becoming obsessed with Wesley Crusher's favorite holodeck program, Harry Potter and the Philosopher's Stone. But there is a strange malfunction in the program. Dementors show up much too early, and the Voldemort character refuses to be shut down.

Harry Potter/Star Trek Next Generation crossover.

Author's Note: This story is written for NoCleverNameForMoony's Criss-Cross Over Challenge.

Rating: K+

...

On a starred night Prince Lucifer uprose.

Tired of his dark dominion swung the fiend

Above the rolling ball in cloud part screened.

...

He reached a middle height, and at the stars,

Which are the brain of heaven, he looked, and sank.

Around the ancient track marched, rank on rank,

The army of unalterable law.

(From George Meredith: "Lucifer in Starlight")

...

A solitary figure stood on a deserted railway platform at dusk. The magnificent scarlet steam engine that had brought him to this remote location was already disappearing behind the mountains in the misty distance.

The traveler glanced up and down the empty platform. He appeared to be waiting for someone. Almost absently, he pulled a hawthorn wand from the pocket of his dark, flowing robes. He studied the wand for a moment and gave it a few hesitant flicks. A small golden spark shot from the tip of the wand, and the traveler stared curiously at the wand in his hand.

Suddenly, a sharp crack rang through the evening silence. Without warning, a boy in school robes appeared on the platform, seemingly out of nowhere.

The traveler nodded. "There you are, Mr. Crusher. I was beginning to wonder if something was wrong."

"So sorry!" The boy sounded out of breath. "I know I was supposed to meet you at the station at eighteen hundred hours, but something came up. There was a troll in the dungeon, you see, and the headmaster insisted that the prefects lead the students to safety."

The traveler smiled ever so slightly. "A troll? I trust your evacuation procedures went smoothly, Mr. Crusher."

The boy grinned. "Oh, they did. But three of the first year students had gone off on their own, and they happened to come upon the troll, which had proceeded to the girls' bathroom. I had to help them get the creature under control."

"Ah. I see." The traveler nodded. "And then of course you had to report those students for disobeying a direct command. I assume you had to punish their serious offense rather severely."

"Erm... Well..." The boy flushed.

The man laughed. "At ease, my young friend. I am just pulling your leg."

The boy looked rather relieved. "That's... very funny, captain..."

"Professor," corrected the man mildly. "I am the new professor, remember? I believe you came down to the station to escort me up to the school?"

"Right." The boy nodded and smiled. "If you will kindly follow me, Professor Picard; I will send my patronus up to the castle and let the headmaster know that you have arrived. Oh, and I am Wesley Crusher, by the way, Gryffindor student and Hogwarts prefect. I am a close personal friend of young Harry Potter's."

"A pleasure to meet you, Mr. Crusher." Picard nodded gravely. "I have heard about Harry Potter of course; his name is quite famous in the wizarding world. I look forward to meeting him. Who else will I have the pleasure of meeting this evening?"

Wesley straightened his school tie. "Well, there are the well-known staff members, of course: Professor Dumbledore who is the headmaster, Professor McGonagall who is transfiguration teacher and second in command, and Professor Quirrell, who teaches Defense Against the Dark Arts. You will be taking over the History of Magic Classes while Professor Binns is on vacation. There are actually quite a few new staff members at Hogwarts at the moment. My mother, Madam Crusher, is a singularly gifted mediwitch. She was fortunate enough to obtain a position as assistant to the Hogwarts matron, Madam Pomfrey, and there are several new professors as well, filling in for staff members on leave: Professor Riker is in charge of the flying lessons, Professor Worf teaches Care of Magical Creatures, Professor Troi teaches divination..."

"Divination?" Professor Picard smiled a little. "Yes, I imagine Professor Troi would be rather good at that."

"And then there is of course Professor Snape, the Potions master."

"Snape?" Picard lifted an eyebrow. "I don't think I am familiar with that name. I'm afraid I didn't get very far into the book; there were some other pressing matters I had to attend to. We are approaching a rather curious nebula, and we are getting some strange anomalous readings in this sector."

"Oh, that's all right, capt... Professor." Wesley grinned. "Professor Snape is a... remarkably pale gentleman. You may find him familiar."

"Ah." Picard smiled now. "I expect I shall."

Wesley pulled a holly wand from his school robes and flicked it. "Expecto patronum!" A brilliant silver form sprang from his wand. It hovered for a moment in the air before it disappeared into the gathering twilight.

"Very impressive, Mr. Crusher," said Picard softly. "Now, what exactly was that?"

The boy smiled. "My patronus, Professor. It's a mountain lion. It's a rather difficult spell to master; it took me months to get it right. A patronus is very useful; you can use it to send messages to other wizards, or to defend yourself against dementors, which are these soul-sucking dark creatures."

"Oh, dear." There was a twinkle in the professor's eye. "I will have to practice that spell, then. Now, how do we get up to the castle from here?"

Wesley pondered for a moment. "We can ride in carriages pulled by invisible spectral horses, or we can simply apparate up to the front gates."

"Apparate?"

The boy nodded. "It's a very efficient form of transport, sir. It took forever to get the program just right, but I came up with a way of combining transporter technology with extra gravitational fields to replicate the authentic sensation of being crushed while apparating. It's a really amazing experience, once you get used to it. I just got my apparating license, so I can bring you up to the castle in a side-along apparition. I would not recommend you trying this on your own until you have gone through the practice sessions - we don't want you to end up splinched, like poor Professor Snape."

"Splinched?" The traveler let out a little chuckle. "I'm not sure I like the sound of that."

"Oh, it's not that dangerous," said Wesley quickly. "It's similar to an imperfect rematerialization when transporting. Professor Snape accidentally left a few circuit boards behind the first time he tried. He was able to re-attach them properly in the end, though."

"Glad to hear it, Mr. Crusher."

The boy took Picard's arm. "Now, hang on tight, Professor..."

...

A moment later, the two of them were standing in front of a castle, so grey and ancient that it seemed to have grown out of the rugged landscape that surrounded it. The sun was molten gold at the horizon, and the castle was a black silhouette against the dark violet shades of evening. A high wrought-iron gate swung slowly open before them as they approached.

"Welcome to Hogwarts School of Witchcraft and Wizardry, Professor," said the boy softly.

Picard glanced up at the castle, still massaging his chest. "Perhaps you might consider reducing the gravitational pull during the apparating procedure just a tad, Mr. Crusher..."

Wesley grinned. "Oh, come on, sir, what would be the fun in that? Now, follow me, Professor."

They crossed the darkened grounds and climbed a crumbling staircase made of weathered stones. Wesley pushed open a massive oaken door, and they stepped into a vast torchlit entrance hall.

"This is a rather impressive program, Mr. Crusher." Picard's voice echoed among the ancient stone walls.

Rapid footsteps could be heard against the flagged stone floors now, and a dark-clad man came striding towards them. His face, pale as ashes, seemed oddly bloodless, and it created a startling contrast to his limp night-black hair. His face registered no change in expression as his glance fell on the man and the boy who had just entered.

"Captain-"

"Oh, Professor Picard, if you don't mind," corrected the new professor gently. "I assume I have the pleasure of meeting Professor Snape?"

The pale man nodded stiffly. "I think you had better proceed to the Great Hall as quickly as possible, sir. We require your help."

Wesley stared at him. "Our help? With what? The troll has already been captured."

"The troll is not the problem, Mr. Crusher," said the pale professor in the same emotionless voice. "There are dementors in the Great Hall, and I am afraid that I am not capable of casting a patronus to help repel them. They cannot affect me, but I cannot affect them either. The teachers and the older students are doing what they can, but I am afraid they are vastly outnumbered."

"What?" Wesley looked almost as pale as the professor at this point. "Dementors? But that's not supposed to happen, Data! The dementors are not part of the program for this level; they don't enter until Year 3. Something is terribly wrong!""

"Then we had better come to the aid of our crew members as soon as possible." Picard looked grim. The three of them ran together over the flagged stone floors, and Wesley flung open a large wooden door.

The next moment, they were surrounded by fluttering dark shapes, pressing in on them from all sides, and terrified shrieks rent the air.

"What is this?" Picard's voice was hoarse. "Why is it so terribly chilly in here? I feel... Oh, God, what are these terrible things? They are all around us. This is a lot worse than apparating, Mr. Crusher. "

"Computer, freeze program," whispered Wesley. "Oh, I hope Mum is not in here... "

A soft voice rang out overhead: "Unable to comply."

"Override code Picard 542." The captain's voice was trembling now. The dark shapes, hundreds of them, were closing in on them now, like a suffocating spectral shroud.

"Unable to comply," repeated the disembodied voice sweetly.

"Quick, Mr. Crusher - tell me how to cast the spell to repel these creatures," gasped Picard, twisting and turning to get away from the dark figures that surrounded him. "Mr. Data, these creatures don't appear to affect you. Please locate Dr. Crusher and our other crew members and bring them to safety if you can."

The pale man nodded and vanished amid the eerie dark forms.

"Focus, captain," breathed Wesley. "You have to point your wand at them and focus on a positive memory while you utter the incantation Expecto Patronum. But it's not easy; it took me a long time to get it right. Maybe you'll be able to do it faster... "

The captain nodded briefly and closed his eyes. He stood completely still for several moments while the sinister wraith-like figures wrapped themselves around him. Breathing deeply, Picard opened his eyes, flicked his wand and said calmly: "Expecto Patronum!"

A shimmering opalescent cloud burst from his wand, and slowly, the cloud began to assume a shape. It was indistinct at first, but soon it brightened and became more recognizable. It was a lion.

At Picard's side, Wesley spoke the same incantation, and soon the captain's lion was joined by the luminous shape of a young mountain lion. The two light-creatures moved through the vast hall, and the dark shapes of the dementors shied away from them, as if in revulsion.

The man and the boy walked slowly through the hall, wands held high, blazing a path through the seething sea of dementors as they walked. Several other silvery shapes were joining the two patronuses now; there was a brilliant phoenix, a luminous cat, and a few other more indistinct shapes.

There were students everywhere, cowering under the tables or lying on the floor. A few of them rose to their feet and attempted to produce patronuses of their own.

An ancient man with a long silvery beard was attempting to keep the dark dementors at bay, and his voice rose over the terrified whimpers of the shivering students: "Students, do not panic! If you are incapable of producing a patronus, stay low. Those of you who can, join me in driving these dread creatures out the school."

Slowly, ever so slowly, the dark shapes were forced back. More glittering patronuses banded together now; they joined ranks and drove the dementors slowly but surely out of the room. The dark shapes sighed and whispered all around them for another moment; then they rose to the ceiling overhead, floated through it, and disappeared into the night sky.

"Dr. Crusher, Riker, Troi, Worf - identify yourselves!" The captain's voice rang out through the hall now. Four figures in staff robes emerged out of the crowd.

"Wesley! Are you all right?" A red-haired woman threw her arms around the boy. "I thought... When those creatures descended on me, I was convinced that I had lost you, that you must already be dead... Something is horribly wrong with your program, darling."

"The fear... So much fear..." A young woman, whose pale face was surrounded by cascades of dark curls, spoke in a trembling voice. A man with a beard put his arm around her shoulder. "That was bad," he muttered. "For all of us. I can't imagine what it must have been like for you, Deanna, sensing everyone else's terror as well as your own."

"Damn creatures couldn't even be torn apart," muttered a dark-skinned man with long wild hair. "But that photon wolf that came from my wand got a quite few of them in the end."

A shadow of a smile passed over Wesley's face. "You produced a wolf patronus, Worf? I always knew you had it in you."

"Traditional Klingon meditation helps focus the mind." The man inclined his head gravely.

"Very impressive work!" The old man with the silver beard came up to them now, and he shook Picard's hand warmly. "I am Dumbledore, the headmaster. You must be the new History of Magic teacher." There was a twinkle in his kind blue eyes. "Arriving just in time to witness and be part of a historic event, apparently. Now, how in Merlin's name did these dementors get into the school?"

"That's what I would like to know!" An elderly witch with her spectacles askew and her grey hair sticking out from her head every which way had joined them now. "There are wards up that should have made it impossible for them to enter. And where is our Defense Against the Dark Arts teacher? We could have used him at a time like this."

The headmaster glanced around the hall. "Excellent question, Minerva... Young Quirrell is not here, is he?"

The red-haired Dr. Crusher looked around with a shudder. "Quirrell? That's the one with the turban, isn't it, the one who turns out to be... Oh, enough of this. Computer, end program. Authorization Crusher 637."

"Unable to comply."

Professor Dumbledore gazed up at the ceiling overhead. It looked like the night sky, and faint stars were beginning to emerge against the ink-black darkness. "Now, who said that?"

Picard frowned. "Computer, why are you unable to comply?"

The emotionless voice responded: "One subroutine is still in use."

"Then shut down the rest of the program."

"Processing request."

Slowly, the Great Hall began to flicker, and the students and professors began to fade. Only Wesley, Picard and the four other crew members were left, standing in an empty room with blank white walls.

The computer's voice came quietly: "99.8% of the program has been terminated. The remaining 0.2% of the program is in use and could not be terminated at this time."

"Computer, identify the subroutine still in use." Picard spoke sharply.

The voice was silent for a moment. Then the voice said: "The Dark Lord subroutine is still in use and cannot be shut down."

Wesley ran his fingers through his hair. "What? Er... Computer, shut down the Quirrell character."

"That character has already been shut down."

"What the-?" Wesley was looking rather worried now. "But he is the Dark Lord. Are there any horcruxes activated at this level, then? Computer, please shut down the following subroutines: Tom Riddle's diary, Slytherin's locket, Hufflepuff's cup, Ravenclaw's diadem, Gaunt's ring, the serpent Nagini, and... er... Harry Potter."

"What?" Dr. Crusher looked stunned. "Harry is a horcrux? You can't be serious, Wesley - he's such a nice boy!"

"Long story, Mom. Just read the rest of the books, and you'll see."

"All those subroutines have already been shut down," said the computer softly.

"What?" Wesley looked up at the ceiling, as if hoping to catch a glimpse of the speaker. "But then, how can the Dark Lord's program still be running? Computer, identify all subroutines still in use."

A moment's silence followed. Then the computer's voice said, in the same even tone as before: "The Dark Lord subroutine is the only one still running."

Wesley glanced around at his fellow crew members. "But I don't understand. The castle and the entire wizarding world have been shut down. Where is Voldemort?"

"That information," said the computer gently, "is not available."