WARNING: The following contains spoilers for Batman: White Knight Presents Harley Quinn #6, by Katana Collins, Sean Murphy, Matteo Scalera, Dave Stewart, and AndWorld Design, on sale now.
Batman: White Knight Presents Harley Quinn has been about growth and rebirth for Joker's ex-sidekick. Since cutting her emotional ties to the late Joker, she's embraced motherhood with his twins and a budding closeness with Batman, whose crusade she joined before he got imprisoned. This even allowed Harley to help Gotham's law enforcement as they hunt the Producer and Starlet.
Since her hyena, Lou, got killed in the crossfire, this is taking a huge mental toll on her. Unfortunately, things don't get any easier for her in Batman: White Knight Presents Harley Quinn #6, due to her role in an accidental, heartbreaking murder.
Harley dons a new costume that Batman left her, complete with a utility belt, a retractable hammer and a color scheme that leaves her disguised pretty well in the shadows. However, things go off the rails when she engages the Starlet at a Gotham theater during a film festival. The Producer set it all up to test Harley as a hero, with Starlet wanting to take FBI agent, Hector Quimby, under her wing. As his former nanny, she wants him to become the 'son' she never had, but Harley won't allow it.
She doesn't want to see some warped figure influence a younger person, jogging her mind back to when Joker almost killed Jason Todd. She fought back against the clown then and allowed the Robin to go free and run away. Although she may have saved a life that fateful night, it's not in the cards for this bout.
When Starlet flings her first bolo-knife, Harley's stunned as it bounces off her new suit. Apparently, Bruce made it bullet and knife-proof just like the Dark Knight's suit, which leaves Harley excited. However, she doesn't clear the room of Hector, and she barely has time to react when the second knife is thrown. It deflects off her and hits Hector in the torso, burying itself deep within him. While she and Starlet try to revive him, the agent dies.
Since she and Hector bonded in this series, Harley is understandably angry, but she still gives Starlet a second chance to redeem herself and turn herself in, since that is what Hector would want. He did love Starlet as a surrogate mother from her time as Ethel, and they endured so much abuse from his mom. However, the enraged Starlet tries to attack Harley, blaming her for the death.
In the ensuing fray, though, Harley just knocks Starlet out and has her arrested. Still, as Duke and the cops wrap the scene, this doesn't feel like a win. Harley is sad that Hector was fooled and conditioned by Starlet, which ultimately reminds her of how the Joker locked her into their vicious cycle years ago.