Harper Evans lived an average and unplanned life.
She had recently graduated from college with degrees in computer science and programming, and a random degree in philosophy.
Much to her parents dismay, instead of living and getting a stable career in Seattle, she packed up and moved to the most dangerous place in the US: Gotham City.
In Gotham, Harper decided not to put her college degrees to use and instead, chose to work random jobs that required no skill. This ranged anywhere from working at a hunting equipment store (she got fired because she accidentally fire a crossbow at the manager) to a waitress at a diner (only lasted about a week because Harper's anger and impatience got the best of her).
It was working at all of these random places that caused Harper to meet him.
The self proclaimed "Agent of Chaos".
The "Clown Prince of Crime".
The Joker.