A/N: From the prompt - You are born with the name of your enemy on one wrist and the name of your soulmate on the other. When you meet them for the first time, the name appears. They're both the same person.
When Hermione met Harry he already had both names tattooed on the insides of his wrists. Not that either of them knew at the time which was which. It was only in fourth year that Harry determined that the name "Tom Riddle" was most definitely not his soulmate - that title belonged to Draco Malfoy after all because there was no way in hell Harry was fated to the dark wizard that had killed his parents - and who had subsequently returned from the dead at the end of the tri-wizard tournament - right?
Still, it was all very confusing for him and Hermione tried to help him in any way she could as he railed against the idea of Malfoy being the one for him. So she didn't say anything about the girls he dragged into broom cupboards or the looks she caught him sharing with Malfoy across the great hall and -
She didn't tell him, or anyone for that matter - choosing to cover up the insides of her wrists with glamour charms - that she'd got her tattoos in second year. She knew that he'd never look at her the same again if she told him, if she told anyone, that they were the same. They'd tiptoe around her, throw her pity glances and when Lord Voldemort returned at the end of fourth year she knew that there was no way in hell she could ever tell them the truth, sure that they would begin to keep things from her - create a wedge between them without thinking about it, but blame her for it all.
It wasn't her fault that "Tom Riddle" was both her soulmate and her enemy. That she'd been the one to find an abandoned, waterlogged diary in the girls bathroom on the second floor halfway through their second year and subsequently been pulled into it.
It wasn't her fault that Tom Riddle was charming and handsome and had her wrapped around his little finger by the time third year ended and that by the time fourth year ended she tasted bile in her throat every time she thought about how much she loved him and how much she hated him for doing that to himself. Doing that to her. For being her soulmate and her enemy.
He noticed of course, that she visited him less frequently now, was a little bit more distant in her interactions with him - more guarded. Until one day she appeared pale and shaken and -
"He only had one name," she murmured, not tearing her gaze away from a spot over his shoulder, "except-"
Tom's eyebrows furrowed in confusion. "Who only has one name? Except what Hermione? What's going on? Where have you-"
"It's on his other wrist of course," she sneered, finally meeting his eye. Tom was suddenly grateful that she couldn't hurt him, not physically or in any way that would injure him - he'd left enough bruises along her neck to know that fact - anyway. "And of course it's Harry's name," she spat venomously. Tom didn't understand her anger. "Well," she huffed, crossing the distance between them and yanking his arm forward to grab at his wrist where her name was tattooed, "he has both names now," she snorted.
"Hermione?" He asked, slipping his hand from her grasp and moving his hands up her arms to grasp her shoulders lightly, "What's happened?"
She laughed and Tom, for the first time in his miserable fifty years existence as a horcrux, felt his blood run cold.