You know, the three of us have been living on the edge way too long. When we're not running from the police, we're fending off some costumed whack-job. Gotham is worse than ever. That gives us a choice -- we can get out, or band together. 
- — Catwoman
Gotham City Sirens #1 is an issue of the series Gotham City Sirens (Volume 1) with a cover date of August, 2009. It was published on June 24, 2009.
Synopsis for "Union"
Catwoman is walking through the streets of Gotham still weak from her last encounter with Hush, when she's attacked by a new villain named Boneblaster trying to make a reputation for himself. She's rescued by Poison Ivy, who takes her back to the Riddler's apartment where she's controlling him and staying with Harley Quinn.
Boneblaster arrives again to challenge them, but he's defeated and wakes up the Riddler. The women leave as the Riddler defeats the supervillain.
Catwoman suggests they begin working together, and the Broker finds them a new home at the abandoned Gotham City Shelter for Cats and Dogs. Ivy is suspicious that Catwoman has gotten weaker and questions Zatanna about her recovery.
Poison Ivy hits Catwoman with pheromones and demands to know the real identity of Batman.
Appearing in "Union"
Featured Characters:
- Gotham City Sirens (First appearance)
Supporting Characters:
- The Broker (First appearance)
- The Riddler
- Zatanna
Antagonists:
- Boneblaster (First appearance)
Other Characters:
- Holly Robinson (Mentioned only)
- Jervis Tetch (Phone call only)
Locations:
- Gotham City
- Edward Nigma's Apartment
- Gotham City Shelter for Cats and Dogs
Items:
Notes
- This issue references several events in recent history. Catwoman was kicked into a car by Jason Todd during Battle for the Cowl.[1] Hush ripped her heart out of her chest during Heart of Hush.[2] Following this incident, Zatanna healed her and she gave Hush's fortune away to her friends including Harley and Ivy. This money also allowed Holly Robinson to make a new life for herself, although nothing is mentioned other than that she moved out.[3] Ivy refers to Zatanna's mindwipes, which is a reference to Identity Crisis.[4]
- This issue is reprinted in Catwoman: A Celebration of 75 Years.