A/N: I don't own DBZ or the characters, that honour belongs to Akira Toriyama. I use British English spelling.

Vegeta and his eight year old son Trunks go back in time to warn the past of the Androids' arrival. When the machine needs repairing the two of them are stuck. At least the past has good food! There's just one problem... Bulma begins to fall in love with Future Vegeta, instead of his younger self. Can Vegeta ensure his son's birth, defeat the Androids, and save the world?

"Pass me the spanner," Vegeta mumbled from behind the screwdriver in his mouth. He glared up at the troublesome bolt, tempted to force it into place, but held back for fear of stripping the thread. The last thing they needed was a loose bolt on the journey knocking them off course.

"Twelve or fourteen?" Trunks asked.

"Fourteen."

A small hand appeared, holding the spanner, and Vegeta took it, then tightened the last bolt, using the screwdriver as a lever to keep it straight. He handed the tools back to his son's waiting hand, before sliding out from under the machine, taking a deep breath. Working underneath the time machine was claustrophobic, reminding him of all his years spent hurtling around space in a cramped space pod. Not an experience he cared to repeat.

Vegeta stood up, brushing the dirt off his jeans. Not that it did much good since he'd worn the same pair of pants for three months, and no amount of washing would ever clean them, even if he'd wanted to waste precious water and soap on the task.

Giving up, Vegeta looked at the machine in front of him. After two and a half years of trying to transform Bulma's designs on paper to a physical machine, he was nearly done. The sleek egg-shaped machine was large enough to fit two people - something he'd adjusted the designs for since Bulma had originally only planned on sending one of them back. The sides were a mix of different coloured metals. Not particularly aesthetically pleasing, but if it didn't assist in getting them the hell out of here, Vegeta didn't care. He had let Trunks spray paint the side, and the boy had scrawled 'Hope' across the side, then proceeded to paint stick figures of himself, Vegeta and Bulma on the side in a garish red.

He glanced at his son. He might not be a talented artist, but at only eight years old, Trunks had been surprisingly helpful in building the machine. He grasped the schematic concepts better than Vegeta, and in the two and a half years since Bulma died, every time Vegeta felt like blasting the machine and destroying it because it wouldn't come together like it should, Trunks would make a quiet suggestion on how to proceed, and they would try again.

"We are missing one more part," Trunks said, dropping to his knees to pour over the designs spread out on the concrete floor. "If we can get that, we can give it a trial run."

"Lunch first," Vegeta said firmly, noting the boy's dark circles around his eyes and wondering when the last time either of them had a full night's sleep was. "Then let's figure out how to get the last part."

His son glanced up from the designs and gave him a solemn nod before following Vegeta to the basin in the corner of the sparse bunker they'd called home for the last two years. Vegeta scrubbed the grease out of the scars and nicks on his skin. Trunks did the same, carefully soaping his hands and copying his father almost exactly.

Vegeta dried his hands, then opened the small bar fridge he'd manage to scavenge a year back, pulling out the last of their food. Since the table meant for dining was currently covered in tools, Vegeta made Trunks a sandwich on top of the fridge, carefully cutting off the edge of mold growing on the crust, then slathering it in the last of the butter. He pushed the plate into the boy's hands.

"What about you?" Trunks asked.

Vegeta shrugged, attempting to appear casual even though his stomach had been screaming for food for the last two days. "I'll get more food when I go out for the last part." It wasn't a lie exactly. If he found the opportunity to pick up supplies, he would. Otherwise they'd be leaving soon anyway, and Vegeta knew the past had plenty of food.

Trunks frowned at his father, but sat cross legged on the edge of the makeshift bed Vegeta had made for him out of a pile of blankets, then began to eat, hurriedly pecking at the food like a bird.

Vegeta had plenty of experience in starvation from when he was a child. It had been an easy way for Frieza to get him to do his bidding. The thought of his own son experiencing a fraction of what he did made him feel more like a failure than his inability to defeat the androids ever had. He turned away from Trunks and closed his eyes, leaning on the work bench. The chances of them starving to death were just as likely as being killed by the androids. Every time he went out, he was at risk of being caught, and he grew more and more concerned that eventually he wouldn't come back at all, and Trunks would be left to fend for himself.

He opened his eyes again. No. They were not going to die. Not from the Androids or from a lack of nutrition. He would see Bulma's plan through and get Trunks out of this time, just like he'd promised her.

"We need a supercapacitor," Trunks set aside his empty plate and picked up Bulma's old smartphone. He tapped away on it then turned the screen around and showed Vegeta. "A laptop should have one."

Vegeta studied the image, frustrated at how difficult everything was. Most of Bulma's electronics had been destroyed when she died. Two years ago and she would have probably had the part lying around. "There was an electronics store not too far away," he said, mapping out the directions in his head. "Your mother dragged me along to it a few times."

Trunks opened a panel on the side of the machine. "It goes here. We have a standard capacitor, but it will overload."

"Pack our bags and get them in the machine," Vegeta instructed as he headed for the door. "When I get back, we are installing the part then leaving immediately."

Trunks nodded sharply. "Yes, sir."

Vegeta opened the door and glanced back at Trunks. "You know the rules. Wait twenty-four hours before declaring me dead. Don't leave the bunker until then, if you do, do not look for me. Stick to the plan. Get the supercapa-thing and leave."

Trunks gave him a wavering smile. "See you soon, Papa."

The electronics store was easy enough to find, even amongst the rubble of the devastated city. It was next to one of Vegeta's favourite all you can eat restaurants. Bulma had bribed Vegeta into coming with her multiple times by promising to stop at the restaurant next door. Vegeta picked up a slab of concrete blocking the door and moved it to the side before entering the shop.

Bar ceiling lights dangled from the roof, their florescent bulbs flickering on and off. He started walking around the ransacked shop, searching for any remaining computers. The front of the shop had been looted, probably years ago. Vegeta made his way into the store room and started pulling down boxes. Finally, he found a laptop. He ripped off the back of it, and studied the circuit board for a supercapacitor. Deciding not to risk dismantling it without proper tools, Vegeta pulled out the board and tucked it into his pocket.

Grinning with relief, he made his way back out of the shop, but froze when he heard two sets of feet land behind him.

"Well, well, who do we have here, sis?" 17 drawled.

"Looks like the monkey has finally decided to show his face."

The two androids chuckled as Vegeta turned slowly around.

"Don't you two think you've done enough damage to this city?" Vegeta asked. "There isn't anyone left here to torment."

18 cocked her head, her blonde hair swishing to the side. "You're here."

"And we do love to torment you, Vegeta," 17 said, a wild grin spreading onto his face.

Realising there was no way out without a fight, Vegeta clenched his fists and powered up, transforming to Super Saiyan. "Let's get this over with then."

Trunks put the packed bags into the time machine. The coordinates were set, and the control panel open with tools on standby to put in the new capacitor. It would take Trunks less than a minute to get it in, then the two of them could finally leave.

The sooner the better. Trunks knew they'd run out of food in the area. The amount of food Vegeta had brought in had been depleting over the last month, and Trunks was all too aware that most days his father went without. The quicker they escaped this time, the sooner they could get food. And clean clothes. And a shower. Trunks grinned at the thought. He only vaguely remembered what it felt like to be clean and well fed. Like memories of his mother, they were hazy recollections that he couldn't quite grasp.

Trunks checked his watch. It had been two hours. His father should be back by now. Either Vegeta hadn't found what he was looking for at the shop, and went to another city to hunt for the part, or…

With a frown of concentration, Trunks reached out and felt for his father's ki. Nothing. That meant he was suppressing it. Trunks refused to think of the alternative.

A bang at the door made Trunks jump. He ran to heave open the heavy metal door, letting out a yelp as Vegeta fell through the doorway, landing at his feet. The man's clothes were torn, and his stomach was stained with dark red blood that had smeared all over Vegeta's hands.

"Papa!" Trunks dropped to his knees beside his father.

Vegeta's trembling hand pressed something into Trunks' palm. "Finish… it…" he gasped out.

Trunks looked at the circuit board in his hand, then back at his father. "But… Papa, let me help you."

"Finish it!" Vegeta commanded.

Trunks blinked back the hot tears threatening to fall, then ran to the time machine. He removed the supercapacitor from the circuit board, put it in place in the machine, then shut the control panel and screwed it shut.

"Looks like I found the monkey's base," a cruel voice echoed down the tunnel leading to the bunker.

Trunks gasped and ran back to his father. "Papa, we need to go!"

"Leave," Vegeta choked out, his breath rattling in his chest. "Go now."

"No!" Trunks hauled his father to his feet and dragged him towards the machine.

"I found the monkey and his son! Wait until I tell my sister." Android 17's head poked around the door and he grinned at Trunks. "Sorry about your dad, kid. But don't worry, you can see each other again in the next dimension." His palm rose, ki forming into a small ball in front of it.

Trunks dropped his father and powered up into a Super Saiyan, then threw the biggest ki blast he could summon at the android.

17 blocked the blast, then scowled and looked down at his ripped shirt. "Hey! That was new you little punk." He strode into the room and grabbed Trunks by his arm. "Any last words?"

Trunks threw the android a glare. "Eat dirt, you metal freak," he spat.

17's lip curled in a sneer, his grip on Trunks' arm tightening until there was a sharp crack. Trunks whimpered, his legs buckling under him.

The room erupted with a bright purple glow and Android 17 dropped Trunks' arm as he flew backwards. Vegeta stood beside the time machine, one arm raised still from the blast he'd let lose. His other hand clutched his stomach, blood seeping between his fingers. His chest rose and fell sharply with each ragged breath. He coughed, then his eyes rolled back into his head and collapsed to the ground in a crumpled heap.

"I told… you… to go," he said weakly as Trunks tried to pick him back up again.

"Not without you," Trunks said, gritting his teeth against the pain in his arm as he took his father's full weight to haul him up into the time machine. Trunks climbed in after his father and shut the door, then pushed the button to start it up, letting the air out of his lungs as the machine whirred to life.

Android 17 stirred in the rubble. His eyes widened, then narrowed and he lifted his hand, forming a ki blast aimed at them. Just before the ki blast reached its peak, ready to be released, Trunks hit the launch button and closed his eyes, praying that his mother's design would work.

A/N: I'm back! Couldn't stay away. I know a few people wanted a sequel to It all adds up, but I've had this kicking around in my head for a while and wanted to get it out. Let me know what you think!