I don't have the background, true, but DC did another excellent job of not losing me completely. On the ground, the girls are gathering in Berlin to plan an attack against the Third Reich. Batwoman tells the story of how she and Renee adopted a child named Jason in Spain, and how he was murdered. (Must be Jason Todd.) I love how they add more and more of the modern mythology and make it fit flawlessly into the new continuity. It also means that if you know some DC background, you get a lot more from this.
There's also a second story about Mera and her sister Hila, who is Queen of Atlantis. Her husband is a despot and Mera is determined to take him off the throne. When she gets to Atlantis, she finds another on the throne - another she'll have to fight if she wants to take the throne and right the wrongs of the former king herself.
There's a lot of coming together in the first storyline and Mera's story is more about a family coming apart, from her backstory to the current story. There's a lot going on here, and a lot of small, and personal interactions that I really, really enjoyed. Especially the Harley Quinn/Poison Ivy moment where they smooch. Apparently they're a couple in any continuity - and I kinda love that.