A/N: Thanks to all those who put this story on their favorite and/or alert list. Double thanks to those who reviewed. Now then, I've had this idea bouncing around in my head for a while now.

WARNING: There is some profanity in this chapter. Don't say I didn't warn you...

Disclaimer: I don't own Ben 10 or the quote at the beginning of this chapter. I do own this oneshot.

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"Betrayal can only happen if you love."

-John Le Carre

12. Insanity

He had been gone for 72 hours now. 3 whole days. It wasn't the first time that he had disappeared without a word, but he always came back on the second day. Always. He swore that his disappearances were him just doing some investigative work on his own and sometimes he did come back with useful information. Other times he came back with burns or scratches that she treated.

Gwendolyn, having gone by that name since the start of college, looked back up at the clock as if staring at it would bring Kevin home. She hoped he wasn't hurt, that his body wasn't lying in a ditch somewhere. She hoped that he would come home right now and announce that his investigation had taken a little longer than usual this time around. She wanted him to come home, bearing Chinese take-out or pizza so that the two could eat together.

But she knew she was just fooling herself. He wasn't dead, he wasn't taking longer with his 'investigation', and he wasn't going to come home for dinner.

A doorbell caused Gwendolyn to jump in alarm. Maybe he had lost his keys and had tried finding them before giving up and coming home. The thought was shot down as soon as it surfaced. No need for false hopes.

Hurrying over to the door, Gwendolyn opened to see that it was Magister Prior Ghilhil standing there. She wasn't surprised at the visit, just disheartened.

"Come in, Magister." Gwendolyn said respectfully, opening the door fully to allow the Plumber access into the house. "Do you need anything?"

"No." He shook his head as he walked inside. When offered a seat, he shook his head. "I'm afraid I've got some bad news."

She did not want her suspicions to be proven right. She did not want to hear that Kevin's late-night businesses were not private investigations. She did not want her trust to shatter even if she already knew it had.

When she didn't say anything, Magister Ghilhil continued, "A few hours ago, we found Kevin Levin working in a major heist involving level 10 weaponry. Our forces attempted to capture him, but he ran off, leaving two of our men dead." He paused as if expecting her to comment.

Gwendolyn said nothing. Her worst suspicions had been confirmed. Kevin hadn't been doing investigative work. He had been consorting with criminals. The hints he had brought home had just been cover-ups for the real business. Her eyes closed to prevent any tears from leaking forth.

Magister Ghilhil cleared his throat. "Well, I'll be leaving now. They'll need me to organize a team to search for him."

Gwendolyn opened her eyes. "I'll come."

"No." He answered simply.

"I need to. Magister, you can't just leave me behind while other Plumbers go to hunt after him. I won't have him kill any more people when I have a chance to stop him."

Magister Ghilhil watched her outburst with pitying eyes before replying, "This is exactly why we can't let you go. You're too emotionally attached."

"I can't let him run around! Magister, why can't you understand that I need to go? I need to find him and bring him to justice." She lowered her raised voice to murmur, "I need to know why he did it…"

"I can answer that." Gwendolyn looked up at Magister Ghilhil. "I know you want to believe that he changed from his old days, but criminals often fall back into their old ways. He probably met up with an old partner and fell back into trading. One thing led to another and now we have a murderous sociopath on our hands."

Magister Ghilhil's cold explanation sent shivers down Gwendolyn's spine. She shook her head. "He's not a sociopath. Sociopaths don't care about others. He cared…" She trailed off, uncertainty in her voice. Yes, she had never doubted him before, but the horrible idea that what the Magister said was true, that he really hadn't cared for her, scared her.

"Regardless, we need to find him quickly and I will not allow someone emotionally attached to him to come along. It's in the rules."

Gwendolyn looked away. When it came to the rules, Magister Ghilhil stuck by them. Still, she wanted to try at least once more before he rejected her for good. "I can track him for you."

Magister Ghilhil replied in a firm voice, "I can't let you do that. We don't need someone emotionally…"

Gwendolyn cut in, "Emotionally attached. I know." She sighed. "How are you going to find him?"

"We tagged his ship with a homing device." Magister Ghilhil turned towards the door. "Now I must be leaving. I suggest you stay here and…" He paused, uncertain of what to say to comfort her. Finally he settled with, "Stay safe."

"Can you at least call when you catch him?" If you catch him, she silently thought.

"You'll receive news." The door closed shut as Magister Ghilhil left.

Gwendolyn made it to her bed, the bed she had shared with him, before collapsing. That night she cried herself to sleep, only to awaken to news that Kevin had evaded capture.

--

An entire year had passed and still Kevin eluded imprisonment. Every week she would click on the TV to see news reports on how much Kevin had stolen or how many people had winded up dead because of Kevin or how much property was damaged by Kevin. Sometimes these reports would just show the damage and other times they would show the criminal behind the works. It was painful seeing him like this, with the same exact features of the man she loved except for his expressions. Those differed from amused to cruel to just plain insane.

Going out in public was just as horrible. People who knew her or knew her past relationship with the felon would throw pitiful looks her way and then whisper a few words to their friends. The past relationship between a no longer ex-con and a hero was the subject of hot gossip. It had even been brought up in some of the trashy tabloids that made their living off stuff like this. Seeing the headlines was bad enough, but the whispers of the people around her were always worse.

Fortunately there were people who did not treat her like a subject for gossip or a person to be pitied. Her family and her friends were there for her. Ben had sworn that he would find Kevin and toss him in the Null Void for the rest of his life. Julie had spent many days comforting her, soothing her. Those had been the first couple of months.

Now they had mellowed out. The comforting had stopped because she didn't need it anymore. She could go through her days, functioning normally without the need for someone to tell her it was okay.

Perhaps the worst thing (other than Kevin being evil, of course) was that Magister Prior Ghilhil still refused to let her go on any missions involving Kevin. She was still too emotionally attached to him, according to the frog-like Plumber.

It was about this that Gwendolyn was confronting him on. "Magister, we need to talk."

She heard him sigh before he turned away from his paperwork to face her. "If this is about joining in with the group to follow up on the hint to a trade Kevin's involved in, you can leave. My answer is still the same."

"Ben's going." Gwendolyn pointed out. While he had been banned the first few times, it had only been a month after Kevin's betrayal when Ben had been allowed to join in.

"Ben did not procreate with Kevin." A blush filled Gwendolyn's cheeks as Magister Ghilhil continued on, "Therefore he is not quite as emotionally attached as you are and will not disrupt the mission."

"You think I'll traipse off with Kevin to have sex?" Gwendolyn asked in disbelief.

"No. The rules state that if a Plumber had a previously intimate relationship with a criminal, that the Plumber is not allowed to go along on any missions involving said criminal until proven that he or she is over the relationship."

"I am over Kevin." The look that Magister Ghilhil shot her clearly showed that he knew it was lie.

"Please, leave. If you would like to go out, you can come along on the investigation of the foreign space craft that's been hiding in the asteroid belt."

Gwendolyn sighed, shoulders sagging. "Fine." Maybe if she went on the investigation, they would deem her stable enough to go after Kevin. After all, they couldn't keep her away forever.

Two nights later, when she came home from her investigation (the space craft was abandoned and all the files encrypted), she found out that the attempt at capturing Kevin had failed once again.

--

It was two years since she had received the news about Kevin's betrayal. The gossip that had been all the rage had quieted down to her relief. Kevin still remained out of the Plumbers' hands, committing whatever murders and thefts he wanted to. Unfortunately Magister Ghilhil still refused to let her go.

"Hey Gwen!" An unpleasant voice caused Gwendolyn to turn around and look at the man who had called her name.

"I go by Gwendolyn now." She replied, eyes skimming over the man. At first she couldn't remember who he was. Black hair cut short, black eyes, tall, thin face; then it hit her. "What do you want, Cash?" It took all her energy to prevent a tired scowl from coming to her face at seeing the old bully.

"I know it's been a long time since we've last seen each other and you don't exactly have pleasant memories of me, but would you like to go on a date Friday night?" When Gwendolyn just stared at him in shock, he added, "It might help if you start dating someone else. Might help you get over it."

Was this really Cash? Making a nice offer of help? Or was he just trying to take advantage of any hurt wounds to get to her? It had been two years, but the pain was still there under the surface. Either way, her answer remained the same.

"I'm sorry Cash, but…" There was really no nice way to reject a date, so she went straight out with it. "No. I don't want to be dating anyone right now." Gwendolyn turned around and took a few steps away when he yelled,

"Fine! I don't even want you!"

She sighed tiredly. A few other times, a guy would ask her out, she would reject him, and he would yell that very statement out. It was a pretty good indicator of who actually cared and who just wanted something (for example, Cooper had given hints that he'd wanted to go out with her, but he had never reacted violently when she had rejected his advances).

But Cash didn't stop there. "I bet the reason you won't go out with me or anyone else is because you're still seeing him." She froze in her steps, anger filling her. "You two probably meet all the time in secret to fuck each other." Her shoulders shook with fury, just begging to be released.

She turned around and glared at Cash. He took an uncertain step back at seeing her glowing eyes. In a tight voice, she said, "I haven't seen Kevin in two years. The only reason I would want to see him again is to put him behind bars. Don't talk about things you know nothing about, understood?"

"Yeah, whatever." Cash continued to back up, hands raised defensively.

With that settled, she turned away from him. She didn't cry as she went about her business, walked home, cooked herself dinner, slumped down on to her sofa, and turned on the news.

"27 year-old Cash Langerak," Gwendolyn straightened up on the sofa at the mention of Cash's name, "was murdered this afternoon." A soft gasp escaped her lips. Cash, dead? The same Cash she had seen earlier, the same Cash who had asked her out and then proceeded to insult her? But how… Who would target Cash?

"He was found in the apartment he shares with his friend. The person who found him reported that Cash's body had been brutally mauled. Details on his death will be given later. Nothing was missing from the apartment. Now we'll turn over to John to get the details as he interviews one of the policemen at the scene."

"Thank you, Paul." John replied before turning to the policeman by his side. "So what can you tell us about how the investigation is going?"

"We're dusting the site for fingerprints at the moment. If we find any, we'll be able to identify the murderer."

"Is it true that nothing was stolen?"

"Nothing is missing. There are signs of a struggle, but all the blood belongs to the victim."

"How did he die?"

The policeman didn't reply for a few moments and just as John opened his mouth to repeat the question, he answered, "His body was broken. There weren't any guns or knives used," He shook his head before adding, "The body showed signs of having been electrocuted."

A chill ran down Gwendolyn's side. There was only one person she knew that could electrocute people and use superior strength to kill them. But it wouldn't make sense for him to attack Cash. Cash had never done anything wrong to him, except for the one time with his car and then beating him up with the gauntlet, but that had been several years ago. He wouldn't go back and collect on a grudge from that long ago. She shook the thoughts away. A normal person or alien could easily have gotten a hold of something to electrocute someone.

"Why would anyone do this to Cash? Did he have any enemies?"

"We're not sure, but that's what we're going to find out. We'll be interrogating all his associates for information on what he was doing today and whether or not he had ever made enemies." There was a call from the background. "I've got to go."

Cash was dead. Cash had been brutally murdered on the same day he had asked her out and then said those awful things. Gwendolyn closed her eyes, but she couldn't imagine the scenario. It was just a coincidence. The two incidents did not relate to one another. That's what she kept telling herself, but at the same time, she was planning how to figure this out.

Nowadays she rarely cried, but this night she did cry herself to sleep.

--

It had been three whole years since she had last seen Kevin in person. The police had not been able to figure out the case with Cash. Gwendolyn had tried running her own investigation, but she hadn't been able to locate her prime suspect or figure out for certain whether it was him or not.

She had also started dating again. Jake was a nice guy, completely normal and perfectly okay with the fact that she wasn't completely human. Yes, he was nice and every day Gwendolyn told herself that she loved him. Every day she wondered why those words couldn't be true. If he loved her, why couldn't she love him back? When her thoughts started drifting to Kevin, she would instantly stop herself and say that it just needed time.

Walking through the streets, a familiar figure in a newspaper caught her eye. Gwendolyn paused to look, eyes wide. It was Kevin, but not as the sadistic human she had grown used to seeing in the news. Instead he was a mishmash of alien parts, caught in the camera of some photographer.

Instantly Gwendolyn plunged her hand into her pocket and pulled out her cell phone. She dialed the number and waited for him to pick up.

"Hey, what's up?" Ben's voice trickled through the other side of the phone.

"Why didn't you tell me that Kevin mutated again?" Gwendolyn asked, her voice becoming accusing.

There was a pause on the other line before Ben replied, "I'm sorry. It just happened last night. We were fighting and he absorbed the Omnitrix's energy."

Gwendolyn processed the words quickly. "He just absorbed it? Willingly?"

"Yeah." Ben's voice was grim.

She shut her eyes briefly. He had truly changed if he was willing to become a monster to gain power. Her eyes opened and she stared ahead determinedly. "Ben, I know you've already tried, but you have to get Magister Ghilhil to let me go. I want to help."

"I'll do my best."

"Thanks." Gwendolyn sighed. "And I'm sorry for accusing you. I know you would've told me once you rested up."

"No problem. Well, I better get to work on Magister Ghilhil. Bye."

"Bye." Gwendolyn snapped the phone shut. She could only hope that they would let her go. It wouldn't make sense for them to hold her back especially if Kevin had gained more power now.

In the end, they did let her go. And it ended in failure. Upon arriving at the sight of the illegal trade, Kevin had disappeared. At least they had managed to bust the participants in the trade though the dealer was long-gone, if the criminals' words were to be taken.

Still, it was a start.

--

4 years had passed and it seemed as if Kevin had disappeared into the air. He wasn't present for any of the weaponry deals that the Plumbers busted and he wasn't murdering anymore people. It was as if he had just vanished into the deep depths of space. No one could guess as to why he had done so or whether or not he would be back (Gwendolyn thought he would).

Time had not made her love Jake. Yes, she liked him a lot. Yes, she thought he was nice. Yes, she thought he was good-looking. But she couldn't make herself love him. It was impossible and time had only made her realize that. Still, he was nice and she had fun with him. It wasn't love, but at least it wasn't a horrible relationship. At least people had stopped asking her if she still liked Kevin.

Today Gwendolyn had gone with Alan and another Plumber to check out some reported suspicious activity a few miles north of Bellwood. The plan was simple and it would've been just another mission if it hadn't been for him. If they had knew they would be facing him, Ben would've come along. Instead he was tending his sick wife.

Alan pulled the brake on their van, stopping an abandoned factory. Old crates were stacked precariously around the open yard of the factory. Their dirty surroundings did not catch Gwendolyn's eye because there was something else here. Or better said someone.

A small gasp escaped her as she stared at the large amalgamated creature. She felt her body go still, memories and emotions rushing to push at her. He turned his head away from the deal he had procuring to look at her and the two other Plumbers with her.

A wicked smile crossed his face. "Well, well, well, look who we have here." His voice was deeper than she remembered, morphed by his transformation, but it was still recognizable.

Alan's jaw tightened. "So you finally decided to come back." Flames coated him, turning him into his Pyronite form. "This time we're sending you to the Null Void."

"But we haven't even had a chance to chat yet." With a lightning speed rivaling XLR8's, Kevin moved forwards and hit Alan. The half-Pyronite slammed into the van they had used to get here, grunting at the impact.

Kevin turned his head to look at the other two Plumbers. He opened his mouth, letting out a sonic scream to knock the Plumber down. As he turned around towards her, Gwendolyn broke out of her paralysis and shot a burst of mana at his head.

Kevin's head snapped back. He growled before turning to face her. "Is that any way to treat your boyfriend? You know I've missed you."

Gwendolyn's eyes glowed magenta as she summoned up more mana. "You're not my boyfriend. You gave that up when you became a criminal again." She shot the mana towards him, but this time he dodged it with his XLR8 speed.

He stopped in front of her and Gwendolyn was forced to crane her head to see his leering face. "We haven't seen each in other for such a long time and when we finally meet again, the first thing I get is a mouthful of mana. Don't you have a better way to greet me? A hello, a how have you been Kevin, a kiss?"

Gwendolyn formed a fist out of her mana and used it to slam Kevin a few feet back. He didn't look phased by the attack, just offering her a smile. "What, too angry to speak to me?"

"How'd you ever guess?" Her voice tilted towards sarcasm before she followed in a serious tone. "You betrayed the Plumbers. You betrayed Ben and you betrayed me. How do you think I feel?" She shot more mana towards him, which he dodged.

"Obviously not heartbroken enough to stay away from dating other guys." If she had been paying more attention to him, she would've noticed the jealous note in his voice.

"Jake's got nothing to do with this." Gwendolyn hissed. She glanced briefly at her two allies. Both were occupied with the other aliens Kevin had been in the company of, which meant that she would have to handle Kevin alone. "Kevin, why'd you do it?"

But Kevin ignored her question, choosing to delve more into her personal life. "Do you love him?"

"I said he's got nothing to do with this." Gwendolyn replied before repeating her question, "Why did you go back to being a criminal?"

"You don't love him." A wide smile spread over his Pyronite-like face. "That's why you won't answer me. He loves you, but you can't make yourself love him, can you? Too hung over by someone else?"

It was so accurate a reading that Gwendolyn was left momentarily stunned. Then anger filled her. "I told you my personal life is none of your business!" For the moment, her desire to know why Kevin had started illegal trading again (and murdering and stealing and all that other stuff from his past) was replaced by a desire to place shackles on his wrists and send him deep into the Null Void.

Kevin smirked. "So who do you love so much that you can't return Jake's love? Could it be a certain…?"

Kevin's words were cut off by a large blast from the side. It sent his large body flying into crates, which proceeded to collapse on top of his massive form. Gwendolyn looked to the side to see that her other human partner had succeeded in wrestling away the aliens and had been the shooter. She shot him a smile before turning to look towards the jumble of crates.

"We have to get going." Gwendolyn turned to look at Alan, opening her mouth to complain. "No, look, we can't take Kevin down without Ben here."

Gwendolyn glanced over at the trembling pile. She figured they had a few seconds before Kevin burst out and decided to take his revenge. Her gaze slipped to her teammates. While she would've liked to stay and fight Kevin, she didn't want to risk their lives. And they wouldn't leave without her.

"Fine, let's go." Gwendolyn ran towards the van, slipping into the back along with the other Plumber. Alan took the wheel and immediately gunned the engine.

Gwendolyn looked backwards to see that Kevin had burst out from under the crates. He stared angrily after them, but to her surprise, he didn't pursue. Instead he just smiled cruelly, raised a hand as if to bid farewell, and disappeared into the shadows.

She had a feeling this would not be their last encounter.

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A/N: Alright, this is getting long and I've still got a few scenes left to go… Which is why I've decided to split it into two parts. This is the end of part 1 and the next oneshot I post will be the conclusion.

If I didn't get Cash's last name, I'm sorry. I tried finding it, but I couldn't, so I made it up. If someone knows his real last name, please let me know. His offer to help Gwen out by dating her was a sincere offer because I figured that he would've grown some heart since high school. However, when she rejected it, I figured he would resume a jerky manner to hide his hurt. His death will come up again in the next update, so don't think it's just a random death I slipped in.

Titled Insanity for obvious reasons… Reviews are always loved as are alerts and favorites.

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