Batman, Vol. 1 #613A

Hush, Chapter 6
Bruce Wayne, Selina Kyle, Tommy Elliot and Leslie Thompkins attend a charity gala at the opera which is interrupted by Harley Quinn with a crime far bigger than anything she's committed before. Bruce and Selina battle her as Batman and Catwoman, but she gets away, pursued by Tommy Elliot, who wants her to return a jade pendant he stole from her. By the time Batman gets out into the street, he is confronted by the Joker, standing over Tommy's dead body.
Release Date: 2003