Harleen is part of DC’s newish Black Label comics. They’re more adult in theme than the normal DC roster, and probably most (in)famous for including an illustration of Batman’s penis. While that particular panel created a lot of buzz, I do wonder whether the Batmember sort of…misrepresented what Black Label comics are supposed to be. I confess, though, I don’t regularly buy comics these days. I just grab the well-reviewed trades from the library. Maybe my perceptions are wrong. I digress. 
Everything you need to know about Harleen is right there on the cover. The art is amazing, dramatic, tragic. Harleen Quinzel is a human being struggling to keep it together. This book isn’t a prequel to Harley Quinn or an origin story. It remains Dr. Harleen Quinzel’s story the whole time. She’s a mental health professional used to working with people coping with trauma. After working with some traumatized veterans she presents a paper arguing that mental illness can be a survival mechanism. This idea is enough to fund Lucius Fox’s research, and Dr. Quinzel gets to work with patients at Arkham Asylum.
The usual rogue’s gallery of Batman villains is present, but none more so than the Joker. She is aware of his reputation and previous professionals’ diagnoses of him, of course, but she thinks maybe she is the one to save him. In a rooftop conversation with the batman she asks whether or not he thinks she can be saved. She wants to know why he doesn’t kill. “I can’t give up on them, or myself,” he mumbles before doing that cool thing where he just disappears when you glance away for 80 milliseconds.
This one seems like a tragedy, but maybe not. Maybe it’s about Quinzel not giving up on herself. Pretty profound, now that I think about it!