Spoiler warning! This is book 13 in a series, and really not the place to start. The first book is Rosemary and Rue, that’s where you want to begin, if you’re interested.
Official book description:
Hundreds of years ago, the Selkies made a deal with the sea witch: they would have the sea for as long as she allowed it, and when the time came, she would call in all their debts at once. Many people assumed that day would never come. Those people were wrong.
When the Luidaeg—October “Toby” Daye’s oldest and most dangerous ally—tells her the time has come for the Selkies to fulfill their side of the bargain, and that Toby must be a part of the process, Toby can’t refuse. Literally. The Selkies aren’t the only ones in debt to the Luidaeg, and Toby has to pay what she owes like anyone else. They will travel to the fabled Duchy of Ships and call a convocation of the Selkies, telling them to come and meet the Luidaeg’s price…or face the consequences.
Of course, nothing is that simple. When Dianda Lorden’s brother appears to arrest Dianda for treason against the Undersea, when a Selkie woman is stripped of her skin and then murdered, when everything is falling apart, that’s when Toby will have to answer the real question of the hour.
Is she going to sink? Or is she going to swim?
The Luidaeg, or Sea Witch, may be feared across Faerie, but to October “Toby” Daye, she is her crabby aunt, and very much considered an important part of Toby’s ever growing family. It’s also an undeniable fact that Toby would have died more than once without the aid of the Luidaeg, not to mention mourning her dead daughter. Toby owes the Luidaeg several tremendous debts and couldn’t refuse if she wanted to when the sea witch shows up on her doorstep and announces that it’s time for the Selkies to come to an end, and the Roane (a nearly extinct faerie species) to be born again, through the aid of Toby’s unique magic. Since Toby’s half-human, half-changeling daughter is now a Selkie herself, Toby is concerned about what is to happen, but has no choice but to accompany the Luidaeg to the Duchy of Ships.
Full review on my blog.