Disclaimer: Don't own DP.

And thus begins a new story!

Story Summary: Clockwork said he couldn't change the past or alter the future, but Danny refused to believe that time was so inflexible. He refused to believe he couldn't save Sam from her own death. Partially AU.

Quantum Paradox

Chapter 1

Quantum: (adjective) Latin Origin Meaning: "the amount of/measure of."

Paradox: (noun) Meaning: A contradiction, but ultimate truth beneath the contradiction.

Samantha Manson thought it was a normal day.

Heavy metal blasted from her headphones as she stared out the window of the railway car, watching red and green lights blur in the underground tunnels. A few overhead bulbs on the ceiling flickered.

She looked down to watch the repeating glow of a song name on her mp3, and when she glanced back up at the window, the sight of another body blurring into reality startled her. Green eyes stared back, and Danny Phantom smiled weakly as he flew alongside the railcar at sixty miles an hour. Then, he disappeared.

Sam pulled out one of her ear buds expectantly. Glancing around, she waited for him to appear again.

Up front, the doors to the connecting car opened, and a man in a black suit walked through. He'd looked as though he'd come from a funeral.

But she knew him anywhere, green eyes or blue eyes.

She stared at him in confusion as he quickly walked to her bench. "Danny, what are you doing here? Shouldn't you be at your college for a job interview?"

For a moment, he could only stare. His blue eyes were wide, and he sharply inhaled. Sam felt her face grow hot under his piercing gaze.

Then, he swallowed hard and seemed to snap out of it.

He waved her off. "Don't worry about that," he told her. "In three minutes, it won't matter anyway."

She raised a brow. Something was off about Danny today.

"Look, I need you to listen up," he told her, sitting down opposite of her seat. Dead seriousness reflected in his eyes. As a Fenton, he was rarely ever serious.

Yep, something was definitely off about him. She crossed her arms and raised a brow good-naturedly. "I'm listening."

"That light above you?" he said. "It's going to flicker three times with a power surge."

It did, and it cast shadows over his sad face.

"A baby wearing a red shirt will start crying in the back."

The rail car jolted over an uneven piece of track, and it frightened a poor infant, who began to wail. His mother cooed over him and rubbed his red-clad belly.

"The next song on your mp3 will be Metallica's 'King Nothing.'"

And as the beginning riff softly played from her ear bud she stared up at him with wide eyes. "My mp3's on shuffle. How did you know that?"

Danny shrugged, but it looked painful, as if his muscles were strained. "I've seen it happen before."

She felt incredibly unsettled. Maybe it wasn't such a normal day. "What is this?" she asked, half-joking. "Is foresight a new power, or something?"

He looked haggard. "I wish. God, I wish. But I'm not in power here. I'm just an observer."

The woman gave him a look, as if he'd taken a joke too far. She really hoped no one was eavesdropping on their conversation. "Seriously, Danny, why don't you-"

"-Don't you remember, Sam?" he asked desperately. "We've had this conversation before."

She laughed, but it was nervous. "Danny, are you alright? You're acting really strange, and it's kinda starting to scare me."

He gently pulled away the bud still in her ear, and it fell by the wayside. His touch felt electric. Then he cupped her face between his hands, memorizing every last detail of her worried expression. "No, I'm not alright. I have watched you die four times," he whispered, voice broken and quiet. He knew he was upsetting her. "And I'm still looking for the answer. But don't worry. I'll come back. I'll be back, even if you don't remember it. And I will save you."

"…Wha-?"

He pulled her into a kiss, and she gave a muffled cry, eyes wide.

Danny… was kissing her?

For a moment, it felt good. She stopped thinking about it. She relaxed into his embrace, closed her eyes to feel the pulse of her heartbeat against his, the wild desire held back by mental chains underneath his muscles and fingers, straining to break free and kiss her senseless.

The others in the rail car coughed and glanced away.

Ten seconds.

He pulled away, blue eyes heavy. "I love you," he whispered brokenly. He stroked her face with trembling fingers. "God, I love you so much."

Light from the end of the tunnel-it was sunny outside-shined into the windows.

Her purple gaze searched his, utterly confused and horribly bright with life, beautiful life and love. "Danny-?"

And the world exploded into fire.

News anchor Tiffany Snow appeared unusually grave as the camera focused on her face. "Hello everyone, and welcome back to Channel 4 news. It's been two hours since the horrible tragedy that took place outside of Amity Park city limits. For those of you just tuning in, railway car T-89, eastbound to Chicago, exploded after a break in the fuel line. One-hundred and thirty-seven passengers were killed instantly, including the heiress of the Manson Family Fortune. Over fifty spectators were injured from shrapnel, although there have been no reports of any spectators in critical condition. Police are currently investigating whether the accident was an act of terrorism or a simple malfunction in the system. We'll take you now to ground zero, where Lance Thunder is currently on the scene. Lance?"

The camera broke away, and a new panel zoomed onto Lance's face. The wind ruffled his blond locks, and he held his hand up to his ear. There was a moment delay. "Thanks, Tiffany." He glanced up into the camera. "I'm just outside the tunnel entrance, where rail car T-89 now rests in pieces."

Lance stepped away from the camera, and he motioned to the black debris, which had spilled out of the tunnel and marred the surrounding green grass and shining rails. Ambulance and police lights flashed in the background. "As you can see, damage from the fuel line break was extensive. Numerous medical teams and safety crews arrived on the scene in short order, including hospital volunteers and our very own Danny Phantom."

The mass chaos of teams from different hospitals, departments, and law enforcement created a hum of voices and shouts behind Lance's. If one squinted, one could see a ghost in a jumpsuit helping to lift heavy machinery into the tunnel. He was crying, even as he carried on.

"Unfortunately, our teams have confirmed the one-hundred and thirty-seven death count with no survivors. All families are currently being contacted, and the mayor is drawing up plans for a city-wide vigil tonight for all the passengers of T-89." He sighed. "This is Lance Thunder, still wishing he'd taken that job in Chicago."

Danny fell out of the portal, gasping for air, shaking on the stone floor. Tears streaked his face and burned his emerald eyes. He couldn't breathe, couldn't hear, couldn't think.

He'd failed again.

The hem of a purple cloak floated into the corner of his vision. "Daniel," a calm and mournful voice echoed, "this is tiring you. Your actions are illogical and unhealthy. This was your fifth attempt, and nothing changed." A slight pause of hesitance. "You cannot change the past."

He stared up into the sad eyes of Clockwork. "Like hell I can't!" he bit out angrily. He brushed the tears from his eyes. "I'm gonna change it. I will change it. Send me back."

Clockwork sighed, and he powered down his staff. "Not tonight. You've had enough."

Danny stood on shaky legs. "No!" he argued passionately. "I have to go back! I have to figure out why she and everyone else died! I have to save them!"

"You are obviously too emotionally strained to make logical decisions. Go home," Clockwork said firmly, "or I will ban you from entering this portal."

The Master of Time was incredibly good on his promises, and Danny paled at the threat. "You wouldn't," he whispered. "That would kill me."

"And if you continue on this self-destructive path, you will die," Clockwork advised softly. "Daniel, you need to eat and sleep. You need to spend time with your family. Get out of the Ghost Zone."

The twenty-year old half-ghost swallowed back tears. "I can't leave her, Clockwork."

"You aren't leaving her," Clockwork said. He gestured to the portal, where a frozen image of Sam lounging against the railway seat swirled. "She'll be here."

But it wasn't enough for Danny, because he knew that in present time, Sam was buried in a vault at Amity Park Cemetery.

Even if he came back tomorrow, the Sam in Clockwork's portal to the past would die in a horrible explosion.

And he'd feel the excruciating pain of her death again.

Hey everybody! So this story is kind of an experiment for me; I've seen a couple drabble stories around, and I really liked the idea. This is definitely a concept story, and it's way different than anything I've ever written! It may or may not also have accurate information regarding scientific time travel. J This story is also partially inspired by the movie Source Code, as one can see the parallels, but the plot will severely deviate from said movie in many respects. As a drabble series, it will be periodically updated with chapters probably a bit smaller than this prologue, and the plot will be fully developed as time continues.

Disclaimer: I do not own Danny Phantom, or any aspect of Source Code.

So please review and tell me what you think!

Thanks for reading,

Lightning Streak