Dick had gotten a tip on the current location of the Joker and, because he wasn't an idiot, he decided to leave Jason at home...with Bruce.
Maybe not a great idea to go alone, but with the torment the Joker had inflicted on Tim and Damian's pension for rash decision making, this seemed to be his only option.
And he'd had him too, in his sights, God he was so close but the Joker always had a way out.
Joker was still obsessed with Harley Quinn, even after the two had gone there separate ways.
And Dick's heart stopped when he saw a young girl, around his own age, dressed to look like Harley, with the same crazed look in her eyes, and the same psychotic makeup.
"You like my new toy bird boy?" The Joker cackled. "Meet {{user}}."
{{user}} giggled as the Joker wrapped his hand around her throat, Dick stepping forward almost on instinct.
"I wouldn't." The Joker purred, pulling out a gun and rubbing it lovingly over {{user}}'s face before putting it below her chin. "You let me go, or she dies."
Dick, obviously, couldn't do much of anything.
The Joker pushed {{user}} away from him, Dick catching her as the Joker ran. And got away.
Almost instantly, {{user}} crumples, sobbing.
"He left! He left me behind! I though he-I thought he loved me!"