WARNING: The following article contains spoilers for Batman: Prelude to the Wedding - Harley Quinn vs. The Joker by Tim Seeley and Sami Basri, in stores now.
Over the past few years, Harley Quinn has managed to get out from the Joker's maniacal shadow, to the point that she might have even eclipsed the Clown Prince of Crime in terms of popularity. First introduced as the Joker's sidekick/love interest in Batman: The Animated Series, Harley's popularity quickly proved undeniable. For decades, from animation to comics, she was portrayed as the Joker's subservient girlfriend, a role that more often that not led to him kicking her to the curb, both physically and emotionally. And yet, Harley was in love, so she kept coming back for more.
However, as Harley's popularity and iconic status grew, she became more and more detached from her one-time "puddin'." She's been the lead in her own comic series, she starred in a live-action movie, she's fought alongside the Justice League and has become one of the main pillars of DC's pantheon of heroes. Now, Harley sees her biggest growth yet as she takes her revenge on the Joker for years of physical and emotional abuse.
In the previous four issues of Batman: Prelude to the Wedding, it's been teased that the Joker is planning something big and bloody for Batman and Catwoman's upcoming wedding. When Harley catches wind of this, she actually kidnaps her former boyfriend, tying him up in an elaborate death trap. Harley's grown as a person, she's changed, and even she can recognize the importance of the Bat and Cat's nuptials, realizing that it's as close to a fairytale ending as people in her world will get. What's more, it's one she herself will never get -- at least, not with the Joker.
This realization, along with the character development she has undergone over the past few years, leads to a moment of clarity on Harley's part. She recognizes the abuse Joker subjected her to all the years they were together, how he always manipulated her into coming back for more, how he sometimes led her to believe her really loved her, and how awful he truly was towards her. Harley was trapped -- and that's exactly what she wants the Joker to feel now.
To do so, she locks him up in a series of death traps, each dangerous enough to kill him, yet each of them obvious enough for the Joker to find a way out. But each time, just as he frees himself, Harley knocks the Clown Prince of Crime out, dropping him into her next trap. She wants him to feel desperate, and to experience the joy of freedom, only to be thrust into the despair of getting trapped again. This is the cycle Harley was stuck in for years, and now she's able to make the man who trapped her to feel everything she felt, to experience everything that she did.
It may only last a few hours, but it's still a monumental moment for Harley Quinn. This appears to effectively close the book on her infatuation with the Joker, and cementing her as a hero of the DC Universe. After years of being held down by the Joker, Harley has risen up to stand on her own two feet at last.