All of it

"This is going to be a lot." She said, shifting a little in her seat, causing the mess of cum she made earlier to smear further over her groin area. She bit her lip at the sudden additional stimulation. It took a lot of restraint not to just jump over her desk and pounce her assistant like a rabid animal. "So." She explained, "I've not been as fruitless in my endeavours as it might have seemed. You will understand in a moment. I've not always been truthful about my work and my obsessions in it. You remember when I sent you to get me all those transcripts about writing techniques and famous quills and whatnot across the ages? Yeah, this is about that."

Emma listened intently, ever the studious submissive little...
She stopped herself before that part of her brain could finish that thought, let alone speak it out aloud. She gripped her desk with both hands, trying to focus on the pattern of the simple wood, and nothing else before the unfamiliar pleasures and yearnings drove her insane. To open up about this and the self-indulgent manner in which she had explored that particular treasure was difficult enough.
"Do you know that thing that children do? And adults too, I guess...Writing on themselves, just doodling away, thoughts and ideas. Sometimes taking notes or writing down attributes. Idiot on someone's forehead or a sweet nickname on the arm?"
Emma nodded. "Yes." She said, "I think I know what you mean, I just don't get what's that got to do with me. Or you for that matter."

"Yeah, you will, just give me a second."

Evelynn was this close to standing up before deciding against it. She wasn't quite comfortable leaking cum through thin fabric before she got Emma properly prepared for what the marker was actually capable of. Speaking of which: She raised the accursed thing for Emma's eyes to see. She held it high with the gravitas of an old king's forsaken blade, yet Emma did not then grasp the importance of the little thing. "It's a pen..." - "A marker!" Her boss corrected her, "The marker to be precise. The very same piece of coal, quill, pencil and whatnot else I've been tasking you to keep an eye out for. It's different yet the same."

Before Evelynn's rambling could get any worse, Emma interjected again, clearly a bit uneasy with the way her employer treated a common writing implement like some treasure of ages past. "Are you...sure that you're alright?"

"Fucking damnit, Emma, pay attention! Here, look, I'll just show you."

Jumping the gun, so to speak, Evelynn uncapped the marker and wrote "Perfect Pitch Black Nails" on the back of her hand, slow and steady so Emma could follow the procedure. And, as expected, those nails took on a perfect shining black color, almost deep enough to swallow the dim light of the room.