It was an odd thing, how they all just came to accept that there was a sociopathic madman – mad alien – let loose in their home, spending most of his time banging around in her father's pet project, the gravity simulator. Bulma's indefatigable mother even cooked for him, leaving vast meals in the bare little guest room he had unceremoniously claimed as his own – the same one Bulma had originally put him in when he first crashed on Earth in pursuit of Goku.

Dr Briefs was a scientist to the core; he ignored Vegeta's general surliness and mildly brushed away the knowledge of the Saiyan general's vicious past, in favour of tinkering with all the gadgets and gizmos Vegeta still had as remnants of his time with Frieza's army. Nothing was more important to Dr Briefs than learning and developing new technology. From the very first day he encountered Vegeta, he had nothing to say except, "Your space pod is fascinating!"

And Vegeta, much to everyone's intense astonishment, not the least his own, found himself explaining how everything worked. When she thought about it, Bulma realised she shouldn't have been so surprised that he could engineer his own armour. Vegeta had once been Frieza's favourite general, hurtling around galaxies with no more than one or two companions to take out entire civilisations. If Vegeta had not known how to fix a broken space pod, or repair broken armour and weaponry, or work out the technology of other races, he and his men would have been marooned somewhere long ago. He had survived thirty years with nobody to help him but that immense dolt, Nappa (one couldn't imagine Nappa fixing anything), amid a squabbling army full of jealous officers ready to take his place at any moment. He was nothing if not a survivor, and survival requires intelligence.

Vegeta did not hurt either Dr Briefs or his wife. He occasionally threw massive tantrums, but having Bulma as a daughter had desensitised them to tantrums of any capacity, including planet-shattering ones. And he mostly lost his temper in the confines of the gravity simulator, which absorbed everything he threw at – or in – it.

Largely Bulma ignored him. She had too much on her mind, between Trunks, the android threat, and then finally, the knowledge that the purple-haired stranger who had come to them earlier was her own son from another timeline.

It was comforting to know – and she said it aloud, with glee – that her son would grow up to be such a tall, handsome, strapping specimen. More importantly, he was clearly not his father. He was not an asshole.

Then again, Vegeta had died in that future, so he'd had no time to teach Trunks to be an asshole. Bulma was not entirely sure whether which option she preferred.

Meanwhile, baby Trunks was growing fast, and growing hard to control. Worried about the whole Oozaru threat, Bulma had had Trunks' tail removed. Vegeta noticed this about a week after it was done, but his only reaction was sheer exasperation.

"Did you forget the Namekkian has destroyed your moon?"

"I didn't want to take any risks."

"You goddamn earthlings. See how you'd like it if I fucking cut off your ear." But that was it. He disappeared into his round of train, eat, sleep, train, eat, sleep. He had nothing to say about his son; either the current baby Trunks, or the tall, sad-looking grown up version.

A day came, however, when Trunks wouldn't stop crying. He refused to eat, refused to be picked up (he was strong for a baby, and when he kicked it really hurt), destroyed another crib, and raised his voice to such a yell that Bulma couldn't get near him through the sheer wall of sound. She was alone, trying to work in her home office; she made frantic attempts to call Chichi, but no-one was home. Then, predictably enough, an angry Saiyan prince kicked down the door (and most of the wall) and roared,

"STOP THAT FUCKING RACKET!"

This did not help. Trunks' wails became so high pitched and so immense that Bulma clapped her hands over her ears and cried out, her head bursting. She actually started to black out; then the wailing started to ebb.

Trunks no longer had a tail, so Vegeta could not hold him upside down by it any longer. Instead he had wrapped one large, powerful hand around the child's body and was holding it aloft, glaring. Trunks was glaring back out of his intense purple irids, his little fists and feet flailing. The force of his blows could bruise Bulma, but they of course had no effect on an angry Vegeta.

"What's wrong with him, Vegeta?" Bulma demanded, not quite daring to approach.

"He's angry."

"At what? I've tried feeding him, changing him, cuddling, everything!"

"Cuddling? He's not a stupid human child. He's half-Saiyan."

"That's so bloody helpful! Tell me what to do, you fool, if you want to get back to your precious training!"

"You had to cut off his tail. You stupid woman."

And before she could stop him, before she could even think, Vegeta had slammed the baby into the wall.

Trunks' head bounced off the wall alarmingly. He continued to yell in fury, apparently unhurt. Vegeta did it again – blam. Bulma shrieked and flung herself at Vegeta, who simply smacked her aside as if she were a fly. Blam – a third time into the wall. Now the wall had a dent in it, and Trunks had a bruise already starting to spread across the back of his head. He fell quiet.

Then, to her immense astonishment, he started to gurgle and laugh.

Vegeta impassively stared at the giggling baby in his fist. "Feel better?" he asked his son wryly. "Are you going to fucking shut up now?"

Trunks laughed, giggled, and squirmed in his grasp. When Bulma tried to grab him he started to whimper, and with an exaggerated put-upon air, Vegeta took him back again.

"I don't... what..." she stammered, watching her small precious son wriggling contentedly about in the grip of his maniac of a father.

"The reason you yank on a Saiyan child's tail is to make it feel pain. Then it calms down. Saiyans are not humans. We thrive on pain. You travelled for years with Kakarot when he was a child, you said. Didn't you notice that?"

Bulma could only stare at him. "But I can't.. I can't throw him into the wall like that! It'll hurt him!"

"Then you shouldn't have cut off his bloody tail, woman! They don't grow back, as you know damn well!"

With startling gentleness, Vegeta put the baby back into what was left of his ruined crib. "Did you do all this damage, whelp?" he asked the child. "Well done." Trunks, having been put down, instantly went to sleep.

"He... I... he's asleep."

"He expended all his energy to protect himself when he hit the wall. Now he's calm and he will sleep. When he recovers, he will get stronger and grow faster." Vegeta said all this as though speaking to an idiot, which incensed Bulma.

"Are you telling me Saiyan parents threw children into walls to get them to grow? What happened to you? They couldn't find a hard enough wall?"

"No, as a matter of fact, they could not. Also, woman, unlike my mutilated child, I still had my fucking tail."

And whoosh, he was gone again.

Vegeta forgot about Bulma and Trunks and everything else throughout the battle with the androids, as did Goku. "Definitely a Saiyan thing," Bulma muttered to herself as she worked on trying to find the damned Dragonballs again. Even Goku scared her these days; he was such a far cry from the feisty little boy she once knew. Namek had changed him in a subtle way; meeting Vegeta, perhaps, had also changed him. Goku's origins had always been murky before Namek; he was a funny little boy with unusual strength and power, and a monkey's tail; he turned into a giant rampaging ape at the full moon, and unlike Vegeta he'd never had control over his Oozaru form.

A power level of 2! Barely that of a human!

Vegeta, screaming in the gravity simulator as he beat himself half to death. It terrified Bulma just watching (and she was often watching, partly just to be sure the simulator didn't blow up again, and partly because somehow she gave a shit if he accidentally killed himself). But Goku had a talent Vegeta did not have, which the Prince had figured out. The increase in power Goku received when he recovered from serious injury was far higher than that of Vegeta's. Gohan had inherited this trait, so the harder Goku and Gohan trained, the stronger they eventually became. It was a trait shared by all Saiyans, but Vegeta simply could not catch up. As long as they were all still in active combat, he would never catch up, and it drove him insane.

A Saiyan must be pure of heart to become a Super Saiyan!

Well, Goku was pure of heart. Vegeta was not. Yet... yet wasn't he? He had said it himself – there are different kinds of purity, different ways to achieve a single goal. He certainly had purity of purpose.

Yes, Namek had changed both Saiyans. Vegeta's last confession to Goku – of which he was now heartily ashamed, as he was of any betrayal of weakness – had created a strange sort of bond between them. Vegeta resented it deeply, resented Goku's persistence in regarding him as a friend instead of an enemy, resented what he perceived as the insult of Goku's pity. Goku, on the other hand, had suddenly found himself bearing a greater burden than ever; the heritage of a dead race, the terrible history of a whole world wiped out, and the even greater weight of all the Saiyans who had been left enslaved to Frieza, along with the last Prince, never to be King. (And he never called himself King of Saiyans – who was there left to crown him?) Saiyans ,the most hated and feared race in the universe, used by a megalomaniac as living weapons of mass destruction, foremost among them a tiny five year old Prince.

Goku had never known of his grim ancestry; and when he did know it, it nearly broke him, as it had broken Vegeta long ago, albeit for different reasons. Goku didn't normally think hard or deeply about things; but after Namek, after everyone was safely home and alive, he went abruptly into a period of quiet that had worried Chichi and Gohan deeply. Piccolo was the only one who had spoken to him at that time.

"He's taken it personally, what the Saiyans have done. He never had a history before; now he has one that is almost too much to bear," Piccolo explained one day in a rare bout of candour, pitying poor Gohan's distress.

"I know it doesn't have anything to do with me," Goku said one day to Bulma, relenting from his lonely isolation enough to eat a huge ice cream sundae she had brought with her. "But... but it kind of does, doesn't it? Nothing separates Vegeta from me but sheer luck of the draw. Radditz was my brother, and he was more like Vegeta than he was like me. If I had been born five years earlier, like they were, I would be one of them. Or I would be dead."

"You are nothing like Vegeta or Radditz, Goku."

"Aren't I? Are you so sure? I know I'm not very smart Bulma. You were always the smart one. But I think I lost something on Namek that can't be replaced. When I buried Vegeta I felt like I was burying a brother. I should have hated him – I know he hated me – yet I couldn't. It would have been like hating myself."

Then, all at once he suddenly perked up. Goku was resilient as india rubber, as Bulma well knew, and everyone thought he had just gotten over it. He went back to training, eating and sleeping, went back to alternately adoring his family and forgetting they existed, went back to being Goku, in other words. Bulma, however, now believed something different.

She knew, though he had not expressly said so, that Vegeta had come hurtling down into her backyard that day because he was after Goku. He hadn't exactly come to destroy Goku; he had come to reclaim the pride he felt he had lost the day Frieza killed him. Destroying Goku was the means to this end.

Goku had started recovering, and going back into training, some two months before Vegeta's return to earth. Piccolo had started sensing Vegeta's approach some time before that. Piccolo was more sensitive to ki, but Goku could not have been far behind. He had realised Vegeta had been brought back to life – accidentally, it was true, for he was included in the very general description of 'people killed by Frieza and his men on Namek' who had been brought back by the dragon's wish. Goku had cheered up when he knew Vegeta was not only alive, but coming to get him. Goku had actually been looking forward to it!

And then Trunks came dropping out of the sky too, and the two Saiyans' plans – however unvoiced – were shelved.

Goku actually appeared ecstatic, the other fighters said, when Vegeta boasted he had also achieved the Super Saiyan ascension. It had annoyed, but had not surprised Vegeta in the least. They understood each other perfectly!

Bulma growled, deep in her throat, and was briefly startled by how much she sounded like Vegeta himself.