(A/N: This is my first Dragonball Z fic. After reading a few stories where Future Trunks or Future Gohan either befriends or spares 18, I came up with this. It's an alternate story of what happens in Future Trunks time. As the summary points out, and the title indicates, something happens that allows Trunks to capture 18 and have Bulma reprogram her. But there are still lots of problems that need to be taken care of, including villains that never appeared in Future Trunks' timeline. While Trunks deals with these new threats, he also has to fight off 18, who's taken a real liking to him, while trying to keep her past a secret. I don't want to say any more than that. So, I hope you enjoy the first chapter.)

Disclaimer: I own nothing.

"REPROGRAMMED"

Chapter 1: A Shock to the System

Trunks would say that it was good to be back in his own time, but that wouldn't be altogether true. Most of the planet was in utter chaos. It was hard to believe that two people were responsible for all this. Then again, these weren't normal people.

Android 17 and 18 were extraordinarily powerful beings created by the mad scientist Dr. Gero. And for years they had been terrorizing the planet, killing millions of people.

But Trunks would have no more of it. After traveling through time and becoming far stronger than he could ever imagine, he was ready to put an end to the androids' reign of terror.

The problem was that he had no idea where to find them. Being androids, 17 and 18's power level couldn't be detected, and so the only way Trunks would be able to find them would be when the two murderers came out of hiding for some 'fun'. But he would be ready when they did.

After returning to his own time and reuniting with his mother, Trunks had his heart set on finally saving the planet, and finally taking revenge for his friends and family that had been wiped out.

"Anything yet?"

Trunks looked up to the blue-haired woman. "Not yet. And ordinarily that would be a good thing, but now that I'm strong enough to beat them, I'm anxious for them to reveal themselves." He frowned. "That makes me sound pretty heartless, doesn't it?"

Bulma shook her head. "They don't come out of hiding unless they're causing destruction. It's not your fault that that's the only way you can find them. But once you do, you can make sure that they never hurt anyone else ever again."

Trunks gave her an appreciative smile. "Thanks, Mom. I'll be sure to destroy them both. They've had this coming for a long time."

Bulma nodded. "That's my boy. Just be careful. I know you're a lot stronger now, but don't forget how strong they are too."

Trunks nodded. "Don't worry, Mom. I won't underestimate them." He couldn't help but to grin in anticipation. 'I'll show them the power of a real saiyan. Father, Piccolo, Krillin, Tien, Chiaotzu, Yamcha, Gohan, I promise to avenge you all.'

(-)-(-)-(-)-(-)-(-)-(-)-(-)-(-)-(-)-(-)-(-)-(-)-(-)

A cruel smirk twisted the face of the black haired young man. He was very handsome and would be found very attractive if it wasn't for the sadistic look in his cold blue eyes. Those blue eyes shifted to his twin sister, a beautiful blond woman wearing the same evil grin as she watched the humans run in fear.

"Look at them run." She said. "They're like ants. How many do you think there are?"

17 gazed at the retreating crowd for a moment. "I don't know. I'd say about fifty."

18 nodded. "Seems close enough. First to 25 points?"

17 pointed a finger at one of the fleeing humans. "Single shots."

With a grin, 18 mimicked him, pointing at another human. "Fair enough."

Small energy beams began flying out of their fingertips, flying at the fleeing humans. They were defenseless against the attacks. All they could do was pray for a few a quick death.

The energy blasts tore straight through anyone and anything in their paths. And that included the humans. They were dropping like flies as they androids mercilessly blasted one after the other.

As the people ran, fleeing for their life, the energy blasts rained down around them. One person tripped when an energy blast came too close and went crashing to the ground. They covered their head and shut their eyes, waiting for the inevitable to happen.

18 zeroed in on the person who tripped and took aim. "And this one's 25."

She shot a blast of energy, but before her attacked could hit, another energy blast struck hers, canceling it out, followed by another one taking out her target. 18 turned to her brother angrily, glaring at his childish antics.

"Hey, 17 that's cheating."

17 just smirked. "I never said we couldn't block each others attacks. And while you were busy complaining about unfairness, I just won."

"Jerk." 18 muttered.

17 gave her a cocky grin. "Aw, don't be mad, sis. Look, there's still one left. You can take him out."

18 shrugged. "Fine."

She held up her hand and produced a ball of energy that would surely obliterate everything in its path, but 17 moved in front of her.

"No, no, not like that. Drag it out a bit, have some fun. He is the last person alive in the city."

At speeds too fast for the human eye to see, 17 was suddenly hovering over the single survivor. With a grin, he stomped down on the man's legs, crushing it completely. He seemed amused by the man's cries of pain, and so he repeated the process with the man's other leg.

18 flew down beside him. "Just kill him already."

17 crushed the man's arm. "But it's so much more fun to make them suffer."

18 rolled her eyes. "Honestly, 17, you're such a child."

Her brother raised his hand, gathering a small portion of energy. "Don't spoil my fun, sis. I enjoy prolonging their suffering."

"Whatever."

Ignoring the pleading look in the man's eyes, the murderous android prepared to put an end to the man's suffering.

"Hold it right there!"

The smirk on 17's face vanished as a familiar voice interrupted his fun. He looked up to see the lavender haired boy that had constantly been a nuisance to him and his sister's playtime.

"Oh great, what do you want."

Trunks glared down at the android. "Let him go."

17's smirk returned. He completely ignored Trunks' warning and blasted the man, reducing him to a pile of ashes. "You didn't say please."

Trunks' face twisted with fury. "That's the last life you'll ever take."

18 move a lock of hair out of her face. "Not another stupid 'I'm going to put an end to you' speech. It's getting really old."

But 17 found it amusing. "Pay no attention to her. I enjoy you're heartfelt speeches of righteousness. It makes it that much sweeter to see that hope crushed when we kill you."

Trunks landed a short distance away. "This time it's more than a simple speech. This time I really am going to kill you." His gaze shifted to 18. "Both of you."

"Oh, scary." 17 mocked. He glanced at his sister, who was looking bored with the situation. "You want to take him out, sis, or should I."

18 just waved it off. "Go ahead, have you're fun. Just try not to destroy what's left of the city. I want to see if any of those clothes stores are still intact."

17 rolled his eyes. "Women." He turned back to Trunks. "So, how do you want to die, quick, or slow?"

Trunks' eyes narrowed. "Not this time. This time it will be you who dies."

With an arrogant smirk, 17 took a fighting stance. "You kill me? That's a laugh. You should be a comedian rather than a warrior. Leave the real battles to people like us."

"People?" Trunks repeated. "You're not people. You're monsters. Nothing but psychopathic murderers. The two of you are nothing but demons straight from Hell," he transformed straight to an Ascended Saiyan, "and I'm going I'm going to send you right back there!"

He charged forward. 17's eyes widened in shock as the young half-saiyan vanished from his line of vision. The next thing he knew, an elbow was being slammed into his face, sending him flying backwards. He crashed into the remains of a building, the whole thing collapsing on top of him.

18 raised an eyebrow. 'That was pretty fast. Wonder where he got that kind of speed from all of a sudden.'

She watched as 17 emerged from the rubble, his hand on his aching jaw. He threw his opponent an angry look, wondering where that had come from all of a sudden. "Not bad. You've gotten stronger since the last time we fought."

Trunks smirked at him. "You have no idea how much stronger I've become."

17 snickered. "Arrogant, aren't you? You get in one hit and you think you've got this battle in the bag. Need I remind you that every time we fought, you've always come up as the loser, only allowed to live because you amuse us so." His smile turned into an angry snarl. "But now you've gone and pissed me off, and I don't want to play with you anymore!"

He flew at Trunks at speeds that in the past would have been too fast for Trunks to even detect, but with his newfound power, he was able to avoid the attack. He vanished a split second before 17's fist landed.

The android's eyes widened in shock. "What? Where did he-"

"Right over here!"

Trunks' foot slammed into 17's face, sending him flying. Then he moved quickly in 17's path and kicked him straight up. With an angry growl, 17 managed to stop his momentum. He looked angrily at where Trunks was, but the saiyan was gone. A moment later, Trunks appeared over him and slammed his balled hands into 17's back, sending the android crashing to the ground, creating a large crater.

For a few seconds, 17 had blackened out. He came to right away, but the fact that his opponent had damaged him so badly was shocking. 'What's going on here? How did he get so strong? None of this makes any sense.'

As he crawled out of the crater, he heard 18 call out to him. "Need a hand, bro? Is the big bad saiyan too much for you?"

17's face twisted with fury as he turned on his sister. "Shut up! Just stay out of this! He's mine!"

18 cut her eyes at him. "Then stop fooling around and kill him already."

17 growled as he watched Trunks land several feet away. The look on the saiyan's face was infuriating. He wasn't afraid in the least. He honestly thought he was going to win.

'Foolish boy, I'm the most powerful being in the universe. I'm the ultimate fighting machine. I can't be beaten by a weakling like him.'

Trunks took on a fighter stance. "Are you ready to continue?"

17's eyes flashed angrily. "Don't you talk down to me! You forget who you're dealing with!"

"I know exactly what I'm dealing with." Said Trunks. "Something that's soon to be a pile of buckets and bolts."

17's fists cracked as he clenched them tightly. Then he took a calming breath and forced himself to relax. "You're just messing with me, trying to get me all worked up so I don't think straight. But I'm afraid it's not going to work. You may be a lot stronger, but you're still no match for me. Lets see how long you last when I'm at full power."

There was a loud rumble as the dark clouds overhead thundered. A downpour started, covering the city-turned-battlefield. 18 looked up at the sky with irritation, but 17 and Trunks' attention were on each other.

"17, it's raining." The blond android remarked. "Hurry up and kill him, I'm getting soaked."

17 smirked. "Don't worry, this won't take long."

His hair and clothes began to whip around him as he raised his power. A powerful aura surrounded him as his power continued to increase. Trunks calmly waited for him to power up. He wanted the android to be at full power so that when he lost, he would know that he, the ultimate fighting machine, as he always called himself, was defeated at his very best.

17 cried out loudly as his power exploded out of him. He grinned at Trunks, wanting to see the look of intimidation on the boy's face. But Trunks' expression hadn't changed in the least.

"Getting worried yet?" he asked, wanting to see some sort of helplessness in the boy's eyes. "How long do you think you'll last with me at full power?"

Trunks just grinned. "Since you're an android, I can't sense your power. But if I could, I have a feeling that I will be sorely disappointed."

17 was infuriated. "How dare you! Die!"

He fired a blast of energy. Trunks flew straight up, avoiding the blast. 17 went after him, his fist flying. Trunks easily blocked the blow, but 17 wasn't discouraged, throwing punch after punch. Trunks continued batting away 17's fists, almost as if he were mocking the android's attacks.

'Why do my punches keep missing?' 17 thought angrily.

He threw another punch, only to have his fist caught by Trunks. Then the saiyan threw his own punch, slamming his fist into 17's face. The android went flying backwards, crashing straight through several buildings. Trunks didn't give him time to recover as he fired a blast of energy. The grounded exploded where 17 landed, creating a large cloud of dust. 17 emerged from the cloud, his clothes torn, his face twisted with fury.

18 groaned in aggravation. "17, will you stop fooling around and take this seriously!"

17's fists clenched. 'That's just it, I am taking this seriously. I just don't understand how he's become so powerful.'

Trunks appeared in front of him and 17 flinched at his sudden appearance. "Still think you're my superior?" he asked.

17 growled. "You… I'm going to kill you!"

He went on the attack again. This time Trunks didn't bother blocking the attacks. He simple moved out of their path at speeds too fast for 17 to keep up with.

"Damn you!" 17 cried, gathering up energy. "Just die already!"

He fired a blast of energy. Trunks had been directly in front of him. He couldn't have gotten away in time. 17 smirked when he saw that Trunks was gone, thinking he had completely blasted the saiyan away.

"It's about time." he said.

"Guess again!"

17 gasped and looked up. Trunks was above him, wielding his sword. He swung downward, moving too fast for the android to react. 18 was on the ground watching. The boy's movements had been too fast for her to see. All she saw was a flash of silver.

But what she saw next, she couldn't believe. 17 remained floating in the air for a few seconds, then, slowly, the left and right halves of his body began to separate. She spotted the sword in Trunks' hands and realized that he had cut her brother in half.

Trunks stuck his sword back in its sheath and moved into the center of 17's two halves as they fell away. Raising his arms, he gathered energy and blasted them. Both the left and right side of 17's body were completely obliterated.

18's eyes widened in shock and disbelief. Her brother had just been destroyed. It couldn't be. How could this brat have gained the power to defeat him? It just wasn't possible.

Trunks looked down at the remaining android, glad to see a look of horror on her face. He floated down to the ground and stood across from her. Slowly, 18's eyes settled on him. She no longer saw a toy to play with, or a minor irritation. What she saw was something that could very well mean her death. Lightning flashed across the sky, lighting up Trunks' face, making him look even more intimidating.

Trunks sneered at her. "What's the matter? You look like you've seen a ghost."

"Y-You…" she stuttered. "You killed him. How… How did you…"

Trunks powered up further. "I told you, I'm a lot stronger now. I'm not the same person I was before."

18 looked him up and down. Now that she really took a moment to look at him, she saw that he was different. He was older than he had been since she saw him a few days ago, his muscles were larger too, a clear indication that he had gone through some massive training to progress this far. But the real difference she noticed was his emotional change. She could see it in his eyes, in his movements, in the way he held himself. He was no longer the weak boy that she and her brother had tormented. He was now truly a force to be reckoned with.

But that just couldn't be. Less than a week ago, he had been no match for them. She herself had been able to beat him, and 17 was even stronger than her. So how could he have killed her brother?

Her eyes settled on his sheathed sword. Was it that weapon? No ordinary sword could slay her or her brother. It must be a special weapon. Yes, that must be it. Somehow the boy had made a powerful sword that was capable of taking them out. It looked the same as the one he always had, but it had to be special. He had managed to catch 17 off guard, allowing him to make the strike.

"Now I get it." she said. "It's that sword that gave you an edge. That's how you were able to beat 17. You never could have done it on your own."

Trunks stared at her a moment, getting a feeling of déjà vu. He smirked and unsheathed his sword. "You think so? Was it really my sword that allowed me to win? It's the same one I've always been using."

"Liar!" 18 snapped. "It's the only explanation. You don't have the strength to beat us on your own."

Trunks smirked. "Funny, King Cold said the same thing after I killed Frieza. Said that without my sword I was nothing, that I never would have been able to beat his son without it. You know what that's called? Denial. You're unable to accept the fact that I am stronger. So I'll do the same thing I did then."

Then, quite unexpectedly, he tossed the sword to 18. She caught it, looking perplexed. "What? Why would you…?"

Trunks sneered at her. "Now you have the weapon that you claim allowed me to defeat your brother. Now why would I give up my source of power if that were true?" His eyes narrowed. "I'll tell you why. It's because the sword has nothing to do with it. The fact of the matter is that I'm just stronger than you."

18's eyes flashed angrily. "That's enough out of you!"

She flew at Trunks, swinging his sword. Trunks easily stepped to the side. He kneed 18 in the gut, sending her soaring upward. Then he appeared in the air above her. He hit her with a powerful backhand, sending her flying.

Grunting in pain, 18 stopped her momentum and flew at Trunks, swinging the sword. Trunks easily avoided the swinging blade, infuriating the android further with each miss.

"What's wrong?" he taunted. "I thought it's the sword that gave me an edge. But now you have the sword, and you can't seem to hit me either."

18 growled. "Shut up! I hate you, you bastard!"

She stabbed forward, but Trunks simply moved aside. His fist collided with her jaw, sending her flying again. Once she recovered, she turned to face him again, raising the sword above her head.

"I am going to kill you!"

That's when something that neither of them expected happened. Lightning struck, attracted to the metal of the sword in 18's hand. Electricity flowed through the sword, into her. Powerful volts flowed through her, sending shockwaves through her system. Trunks covered his eyes from the flash of light, but he saw clearly what had happened. Perhaps it was a good thing he had handed over his sword, or else that could have been him.

When the light faded, he saw 18 hovering in the air, unmoving. A few sparks of electricity traveled over her body, leaving her clothes torn and smoking. The look of pain and surprise on her face shifted to one of blank nothingness. Then her eyes closed and she fell from the sky.

Trunks watched her fall, surprised by this turn of events. She crashed to the ground and remained motionless. He stared at her body with an uncaring look on his face. He came down from the sky and landed beside her. She appeared to be unconscious. It didn't surprise him. A bolt of lightning could kill even him. Electricity wasn't like a blast of energy. It could completely fry whatever it struck. Perhaps it short circuited her, or forced her to shut down like the remote Dr. Gero had used.

Regardless of that, he couldn't leave her intact. Whose to say she wouldn't wake up again and begin a killer rampage. And he might not be able to find her again with his inability to sense her. No, he wasn't taking any chances.

Racing his hand, he took aim at her still form. "This nightmare ends now."

He started to gather energy when 18 began to stir. He raised an eyebrow. So she was coming to. Good, he wanted her to be aware of her death. He wanted her to see it coming, just as she and her brother had brutally slaughter the people of Earth.

18 groaned and began to sit up. Her body shivered from the shock it had received, but she had no idea what had happened. Placing her hand on her head, she looked up at Trunks. She blinked a few times, trying to take in the situation.

"What…" She shook her head. "What just happened?"

Trunks smirked. "You were hit by lightning. Seems like the heavens themselves want you dead."

'What does that mean?' 18 wondered. "I was… hit by lightning?" She looked up at the cloudy sky, where lightning once again flashed across it. Then her attention shifted to the destruction of the city. "What happened here?"

Trunks' eyes narrowed. "Don't play dumb. You know what happened here. The same thing that happened all over the world."

18 looked both confused and worried. "What are you talking about? What happened to the rest of the world? Who are you anyway?"

Trunks cut his eyes at her. "You're boyfriend." He muttered sarcastically.

18's eyes widened in surprise. In her confused and frightened state, she hadn't picked up on Trunks' sarcasm. 'Boyfriend? I have a boyfriend?' She shook her head. "What's going on? Why can't I remember anything?"

Trunks began to lose his temper. "Quit fooling around! I'm not buying it!"

18 looked up at him, feeling slightly annoyed. "I'm not fooling around! I have no idea who you are or what the hell is going on. I don't remember anything! Anything! What happened to me?"

Trunks angry frown decreased slightly. He wasn't stupid to be fooled by the enemy. When someone was boxed into a corner, they would resort to anything, say anything to get out of it. But it wasn't what 18 was saying that was getting to him. It was her eyes. Her eyes were different. He had said it before that it was the androids' eyes that truly haunted you. They always had a look of sadistic evil intent in them, no matter what the situation was.

But that look was gone. What he saw was genuine worry and confusion in her eyes, as if she truly didn't know what was happening.

"You really don't remember?" he asked hesitantly.

"No!" she cried in frustration. "Tell me what's happening!"

Raindrops flowed down her face, making it look like she was crying. But Trunks wasn't fooled. He knew that the androids were too heartless to cry. But as he stared into those eyes, now absent of evil intent, what he saw stunned him. Some of those raindrops actually were originating from her eyes. Those were real tears. She truly was afraid and confused.

'So what?' his mind cried. 'Don't forget who she is. What she is. She's a killer. She's murder millions of people, including your friends. Just kill her now and end it. Then the planet will be safe again.'

He began to gather energy, ready to blast her. It was time for this nightmare to end. It was just too bad that so many people had to die. If only Dr. Gero had used his intelligence for good. Then no one would have had to suffer. In fact, the planet would be protected from any danger that may come in the future. But instead he had created these forces of destruction that had taken out everything, even Earth's most powerful forces. Now only he was left.

That's when he came to a revelation. He was the only one left. All of Earth's defenses were gone except for him. If something else came along that was too much for him to handle, then the planet would be completely defenseless.

He stared at 18 for a while, watching as she examined herself, like this was the first time she had seen what she looked like. Perhaps he could use this to his advantage. While 18 was in this state, he could have his mother look at her, and maybe even reprogram her, turn her into a protector. It would be the ultimate slap in Dr. Gero's face, to see his life's greatest achievement become the exact opposite of what he wanted. And if she couldn't be reprogrammed, then he'd simply kill her; he had the strength.

Trunks' fists clenched. He wanted so badly to kill her. He despised her. She deserved to die. But a voice that sounded eerily like Goku's kept running through his head, telling him to use this to his advantage. To think about what was best for the planet and not let his personal feelings get involved. He could always kill her if it didn't work. He somewhat hoped that his mother wouldn't be able to reprogram her so he could finish her off. But for now, he would put aside his thirst for vengeance.

Moving rapidly, he was suddenly behind 18. She continued examining herself, unaware of Trunks' movement. Raising his hand, he delivered a powerful blow to the back of her head. 18 gave a gasp of pain and collapsed.

Trunks sighed as he looked at her unconscious form. It was so tempting to just blast her to pieces. He wanted to so badly. Why did that lightning have to hit? Then he could have just blown her away, plain and simple.

He groaned. "Sometimes it really sucks to be the good guy."

(A/N: There's the first chapter. Surprisingly long. Trunks has managed to defeat 17, and 18 has suffered an… accident. Poor Trunks wanted so badly to kill her, but he's conflicted with doing the right thing. There will be a lot of that throughout the story. Promises of lots and drama and action to come, so please stay tuned, and let me know how I'm doing. Thank you.)