When Jack came to Flourean Fortescue's Ice Cream Parlour, she always ordered a large chocolate milkshake and she spread her work out before her. She liked it, because it was usually full of students who were much too intimidated by her reputation and constant scowl to bother her, but it was loud and lively enough to mask the work she was doing as well. People seemed to just leave her alone. Other places, Quidditch fans might approach her, or she would run into people from work or who went to school with her. It was for these reasons that she chose this as her base of operations on Wednesdays.
Fridays were Diagon lunches with Max. Wednesdays were ice cream work lunch hours. This was how Jack kept herself working, kept herself focused on accomplishing results. And when people risked interrupting her, she saw it as them risking interrupting progress, interrupting results, interrupting good work. And nothing made Jack more angry than people stepping between herself and progress. She had important work to do, and she was an important woman.
So when a stranger attempted to interrupt her, Jack found herself feeling very unmerciful. She openly stared at the woman for a moment, before saying, “You can try again. You can go back to your table, consider joining me, reconsider it, and I will have no reason to publicly humiliate you in front of all of these people here, okay? I’m busy – I advise that you let me remain so.”