Guillem March pulls double duty as writer and artist on this title, and it’s fantastic.  He gets a bit of an assist on dialog from  Marc Andreyko, and while the dialog is very good, the plot and art is what makes this issue special.  This is what Batman titles are like when Dini is at his best.  Yes, there are massive ties to continuity, but they’re completely unnecessary to reading this story.  It has a beginning, a middle, and an end.   There’s no “last time in Gotham City Sirens” or “stay tuned for the next issue!”.  It’s just a well-crafted one and done issue.  If you like Catwoman, Harley, Commisioner Gordon, or especially Posion Ivy, pick this issue up.