"Dad, will you read me a story?"
Vegeta looked over the top of his book to the purple-haired child in front of him, holding a slimmer volume than his own and looking incredibly nervous. He stared at his son for a long time, trying and failing to fight the guilt that he felt nearly every time he looked at Trunks these days. It wasn't a very big book, and Bulma had told him to spend more time with Trunks that didn't involve training. It was just reading someone else's words. What harm could there be?
"Fine," he said shortly, holding his hand out for the book. Trunks' expression brightened, and then, before Vegeta could react, he scrambled up and made himself at home in his father's lap. Vegeta froze, for he had never been this physically close to his son that he could remember. Even that hug, the first hug he'd ever given him, had been a one-armed affair, for all that he'd let it draw out as long as he thought he could get away with. This was… intimate, familial, and a little uncomfortable. Trunks was nearly nine years old, and heavy with Saiyan muscle, and his hip bone was digging right into Vegeta's stomach. He adjusted his son as best he could and took the book from him.
"'The Erlkonig'," he read, and frowned. "What the hell is that?"
"I dunno," Trunks answered, wiggling in place to make himself comfortable. "It's some kind of fairy tale, Grandpa said."
"Hn," Vegeta said, and opened it to the first page. The illustration showed a man and a boy atop a horse, riding through a dark forest. "'Who is there?'" he read. "'Who rides so late through the dark forest? It is a father and his boy, clasped tightly to him. He keeps him safe, he keeps him warm.'"
Urgh. This had his in-laws devious meddling written all over it. Vegeta turned the page quickly. This illustration was nearly identical to the previous one, except out of the dark forest, drawn in broad brush strokes and scratchy pen, a pale white face leered out at the boy, who looked terrified—and rightly so, Vegeta thought. The thing looked like it wanted to either eat the boy or rape him, he couldn't tell which.
"'My son,'" he read, holding himself rigid as Trunks wiggled some more, "'why do you look so frightened?' 'It is the Erlkonig, my father. Do you not see him?' 'My son, don't be foolish, it is only a wisp of fog.' What a moron!" he exclaimed, feeling Trunks' head sliding against his chest as he turned to look up at his father. "It's right there in front of him. Doesn't he have eyes?"
Trunks giggled, and Vegeta, grumbling, turned to the next page, which showed a close up of the eerie face, now beckoning.
"'My child, my dear one, come with me! I will play lovely games with you, and give you many pretty flowers.' Fuck, Trunks, if something like that ever comes at you, you don't give it a chance to speak, you punch it in the face as hard as you can, you hear me?"
Trunks giggled again, but he nodded solemnly.
"'Course."
"Right."
He read on, the son pleading with his father to notice the strange figure that kept beckoning to him, the father continually not seeing what was right in front of his face, and the Erlkonig making promises that grew more and more elaborate and creepy. Eventually Vegeta turned to the last page, where the father finally reached his house only to find that his son was dead in his arms, the Erlkonig apparently having taken his soul. He shut the book with a snap and frowned.
"Never take a recommendation from your grandfather again, boy," he ordered, looking down at Trunks, who looked back up. "Go get me another."
Trunks about leaped out of his skin. "A-another? Another book?"
"You heard me! And pick a good one this time." He didn't have to say it twice. Trunks had bounced off his lap to go get another book. Vegeta took the opportunity to readjust himself, vowing to keep the boy from digging his elbows into his chest this time. He sighed and laid his head on the seat back.
He had always been split between wanting to help Trunks reach his full potential, and being deathly afraid of taking all that beautiful potential and screwing it up beyond repair. His son had achieved the Super Saiyan transformation at a mere eight years old, was as smart as his mother and as canny and calculating as his father. The only flaw he had was that ridiculous purple hair, and such a thing (clearly) did not prevent him from being far superior to any Saiyan child before or since. It bothered him greatly that a child with such enormous potential had been placed in the care of someone as broken and harsh as himself. He had once been a child of great potential himself, and he had indeed achieved greatness, for all that the fool Kakarot kept surpassing him. His deeds were still great, still magnificent, no matter that there was another that could match him in his greatness, but Vegeta knew also that behind his great deeds lurked a man, flawed and sometimes very stupid, full of pain and hate. He had never wanted that pain for his son, never wanted him to grow up as miserable as he had. Every time his son smiled it felt like a hard-won victory, but lately those smiles were happening more and more.
Trunks ran back into the room, carrying an armful of books, smile wide upon his face, and scrambled up on Vegeta's lap again, where Vegeta picked him up and set him down in a much more comfortable configuration. His son handed him a book, and he opened it and began reading, reflecting that if he had known how easy it was to make his son happy, he might not have been so afraid of trying.
Based on the cover pic, which is not my art.