Disclaimer: Don't own, wish I did.

A/N: Thanks to Lightning Bird for betaing for me.

Dexter could remember waking up the first day in this chilled, dirty cell. He had been confused at first, the pain in his head not allowing him to think clearly. Sitting up slowly, he felt some of the fog lift as he got a good look around. He was in a cell with high walls, a stalactites-filled ceiling and only one bared door. The walls were covered in a glowing film of Fusion Matter, which caused the cell to be cast into a permanent twilight. Trying to rise, he realized just how weak he was, knowing that a head injury won't make him this way, (after all he had plenty from blown-up experiments) he decided that the Fusions must be using a device to drain him of his energy.

Finally making it to his feet, Dexter stumbled over to the door, and hanging on the bars for support he looked out at his new surroundings. He saw that his cell was part of a circle of ten. Across from him was a hall and he could see more cells at the end of it. Looking at the two cells on either side of the hall, the redhead was dismayed to see Blossom and Bubbles curled up in the center of the floors, before he could call out to them a monotone voice drew his attention.

"Looks like they finally caught you, huh, Brainiac."

"Mandy!" Dexter said, his surprised gaze snapping to the left, where he could now see her standing at the entrance of her own cell.

"Thought I was dead, huh?" said Mandy. "Hate to tell you, boy genius, but none of the missing heroes are dead." As she finished, he watched as several shapes began to move forward. In the cell between Mandy and Blossom, Kevin Levin gave him a nod of greeting, while in the cell next to Bubble's was a very disgruntled looking MoJo JoJo. On the other side of Mandy, the redhead could just make out the edge of another figure before a hand stuck out in a tired wave.

"Salutations, Dexter. Dismal accommodations won't you agree?"

"Yes, Double D, very dismal." Dexter couldn't help the faint smirk that crossed his face. After all Double D was one of the few that could rival, if not surpass him, in being OCD about cleanliness and organization.

"Oi, keep it down! Some of us would like to rest before the Fusions come again." Dexter frowned at hearing the familiar voice of Number Four, but before he could respond, an even better recognized (and though he would not admit it out loud) missed voice spoke up.

"You don't have to be such a meanie, Number Four. We're just trying to make this place less scary."

"DeeDee!" exclaimed Dexter, as he reached to his right through the bars, and was met by another hand that latched onto his and squeezed hard.

"Hi, Dexter." Before the siblings could say more, there came three short high-pitched whistles from down the hall.

"That's the signal that the Fusions are coming. Better get back to the center of your cell, Einstein. If they realize we've been talking, they might increase the energy drain on us," explained Mandy, as the others melted back into the shadows of their cells. Nodding once, Dexter gave his sister's hand one more squeeze before shakily making his way to the center of his cell, and sitting down adopted his best poker face. Since he was facing the hall, he was the first to see the Fusions, and growl tried to force its way out when he saw that his doppelganger was leading the group. Coming out of the hall, the Fusions spilt up, each one going to stand in front of a cell. As he fake stopped at his door, Dexter could see the hate, and merciless glee housed in the Fusion's red eyes.

After that day, Fusion Dexter seemed to go out of his way to try and torment Dexter. He was shown scenes of battles being lost, and people being hurt or taken. The worst act was when his mimic would ignore him and enter his sister's cell. Her whimpers and cries of pain would push him to the brink of madness, since he knew there was nothing he could do to help her. Once the Fusion left, it broke his heart that all he could do for his sister, was hold her hand while she cried. Through all this only two things kept him from breaking, the knowledge that he had to stay strong for DeeDee, and the certainty that his friends were rebuilding his time capsule.

One day, as Dexter sat in his cell thinking over escape plans, the signal for the arrival of the Fusions sounded down the hall. Though it was earlier then they normally came, (at least he thought it was, it was hard to tell when the place was kept in twilight) it was no surprise to him, to see his Doppelganger leading the way. What did surprise him was to see three Fusion mechs, instead of the normal group of fakes flanking Fusion Dexter. The boy genius tensed as two of the mechs entered his cell, and forced him to his feet, before pushing him out to stand in front of his double.

"Dexter?" Turning toward the worried voice, Dexter gave his sister what he hoped was a reassuring look, before he was pushed down the hall. As they passed each group of cells, Dexter tried to see if he could recognize anyone in them. Most of the cells were too shadowed for him to tell who was in them, some he could just make out the person. He saw Trex, the Scotsman, Courage, Juniper Lee, Number One, and Bloo, but it was seeing two familiar people in the last set of cells, that caused him to break away from his escort.

"Professor! Ben!" called the worried boy, as he came to a stop in front of their cells. Professor Utonium slowly looked up from his curled up position. He was dirty, haggard-looking, and there were more worry lines then before on his face, but he still managed to give Dexter a small smile of recognition. Relief filled the young teen, to see that smile, but it quickly turned to dismay as he realized that Ben hadn't even flinched at his call. The older teen lay on his back in his cell, his signature green jacket was gone, he was covered in dirt and cuts, and Dexter could see that the Omnitrix was dark on his wrist. If it wasn't for the fact that he could see the slight rise and fall of the burnet's chest, he would have thought him…..

Cutting off such thoughts, Dexter moved towards his friend, only to be grabbed and roughly spun around. The redhead didn't flinch as he met the cold, hate-filled gaze of his mimic. In fact, Dexter's glare got sharper, as he noticed the pleasure the Fusion was getting from watching him. Finally breaking the staring contest, Fusion Dexter shoved his good counterpart back into the middle of the Fusion Mechs before continuing their journey down the hall.

After leaving the cave-like prison room, they walked down a long, straight hall before they entered a new room. The ceiling was high and domed, and the floor was a pool of Fusion Matter with a single piece of land rising from the middle of it. In the shadows cast by the pool, Dexter could see the glow of hundreds of red eyes, and all of them seemed to be focused on him. As they approached the edge of the pool, a walkway rose up out of the Matter, and formed a path to the top of the dais. Climbing the path, Dexter had to fight not to gag, as the foul smell of the Fusion Matter became nearly overwhelming. Moving to the center of the island, Dexter was forced to his knees facing a large, black faintly glowing figure, who's could, madness filled eyes seem to try to pierce through Dexter's soul.

"Dexter," said a voice that was filled with such hate, such hunger, such evil, that it sent shivers down the boy's spine. "Who is this girl? What is she up to?"

Images started to play out in the air in front of him. It took only a second for Dexter to recognize his friend from the past. He could see that she was fighting alongside the KND, against the Fusion Spawns near Hero Square. As she fought the spawn, and then the Shocktanglers, Dexter watched as she would turn and almost seem to be looking straight at them. After a moment, she would snarl in annoyance, before turning away to fight the next group of Fusions. Her behavior didn't surprise the boy genius any, he already knew that she had an uncanny ability to know when she was being watched, (he had done several experiments on that fact, and had drove her nearly nuts in the process) and was surprised that she had only snarled at them.

For a few minutes, Dexter was confused, since he had expected her to be gathering materials for his time machine, and then he suddenly realized just how smart she was being. To keep Fuse from knowing what she was doing, his friend was mixing each part of his machine up with random items that she was gathering for the KND. The importance of each item was hidden, thanks to the disrupter fields around each of the safe zones. Not only did it keep the Fusions out of the areas, but it apparently kept Fuse from spying. Since each time she returned to one of the protected areas, the image would get fuzzy, and then fade all together.

Dexter made sure nothing showed on his face as she fought the Fusion doppelgangers and added three more nanos to her collection. He noticed that each time she added a nano, she would look right at them, and a smug smirk would cross her face before she turned back toward the Fusion portal. The last scene that he was shown made it impossible for him to continue to hid his own smirk. It showed her in the junkyard picking up the head of Larry 3000, as she started for the exit; she suddenly stopped and once more turned to where she was looking right at them. Slowly a wide grin spread across her face, and she said two words, before spinning and sprinting for the exit. He felt his own smirk grow as he read her lips, now knowing why Fuse was showing him this; he wanted to know what she meant when she said 'Mission Accomplished'.

"That, Fuse, was my friend completing my time machine. She's going to back to the past to warn everyone about you. You'll never win now." Dexter could hear the superior tone in his voice, as he faced Fuse fully, and wasn't surprised when he heard his double growl in anger. What Dexter didn't catch was the movement of him raising his wretch into the air. So the boy genius was unprepared for the pain that exploded along the back of his skull, and as he heard Fuse give a furious yell, he once more fell into darkness.

Dexter awoke later in his cell to a voice weakly calling his name. Fighting the ringing in his ears and the pounding of his head he pulled himself to the front of his cell and grabbed the hand he could just see trying to reach around the edge.

"Dexter, what's going on? It's like everything keeps fading in and out." He could hear the fear in DeeDee's voice and wished there was more that he could do for her.

"This timeline is ceasing to exist, DeeDee." Realizing she may not understand him, he went on before she could interrupt. "Our friend from the past, she has gone back and is changing our future for the better, so this future is fading away."

"Will it really be better, Dexter?" asked DeeDee, hope filling her voice for the first time in a long time.

"Yes, sister, it will be much better." His tone was tender, and you could still see a fond smile pulling at the edge of his lips. Though deep down he was truly frightened at the thought of fading away, and losing his sister for a second time.

"Good. You're always right, Dexter, you'll be right this time too." Her voice sounded so far away, and then Dexter realized he could no longer feel her hand in his. Pulling his empty hand back to his chest, Dexter rolled over so that he was facing the ceiling, and let out a very tried sigh. Closing his eyes, he could feel himself slowly fading, a strange sensation to be sure, but as he heard the furious yell of Fuse echo down the hall, Dexter couldn't help the bitter smile that crossed his face.

"I told you, Fuse, you will never win."