One day when the Joker is sent to Arkham, after he killed his last doctor, he is assigned a new employee who just got her degree and he is her first patient- Doctor Harleen Quinzel. She does her best to try and fix the mad man, and she, better than anyone before hand, actually finds an understanding of his psyche, specifically his obsession with Batman. But in her research and digging, she begins to believe she is in love with him, and he uses this to his advantage and plots a way for them to leave together, and become Bonnie and Clyde. She agrees and they successfully escape, and he turns her into his love struck puppet, Harley Quinn.
