This series was originally planned to be only a duology.  I’m glad that Kendare Blake decided to extended it two more books because it’s truly delightful.  Two Dark Reigns begins a few weeks after the end of of One Dark Crown.  Katherine is crown Queen of Fennbirn.  Mirabella and Arisone escaped the island and trying to fit in on the Mainland. Jules is reeling from the death Joseph and is back and Fennbirn.  The island is shielded by the Mist but the Mist is acting up and turning on the island.  Probably because Katherine became Queen without actually killing her sisters and still possessed by the dead queens of the past.  Her sisters escaped the Island and Jules is being propped up as the symbol of a new revolution.  I still like the original Queens Katherine, Mirabella and Arisnoe and Jules is growing me but she’s still not favorite.  Jules is legion cursed.  Meaning she has two gifts that will make her crazy because her powers are so strong.  This is partly why people think she is also a queen and that the Goddess of the Island is trying to change the bloodline of the Queens and change the course of the island.  Of course the Island has another idea.  Mirabella and Arsione may have escaped the island but the island isn’t finished with them yet.  Arisone is being sent visions about the Blue Queen who created the Mist.  She is haunted by her that forces them back.  Jules and her new warrior friends are in direct conflict with each other.  We still Queens against Queens but the battle lines are drawn and the fate of the island is at stake.  Let’s just say, the last book is going to be a doozy.