The Fourth Realm (Realms Gate)

Book 4 in the Realms Gate series focuses on a new generation.
Like their mother, Erin's daughters are having anything but an easy time.
Her eldest, Arianna, is about to turn eighteen and has yet to receive any powers, other than the ability to irritate Damon of Vasmaar. Being heir to the Lokranor throne, she's eager to prove herself worthy of the position. When Damon raises the possibility of a missing realm, Arianna is more than willing to help him find it. As long as she can stop herself from knocking him out flat.
Katya accidently discovers the gateway to the missing Fourth Realm when Ulrik crosses over. Could his presence and her startling new powers have something to do with the rather unusual stone she has picked up? As Katya and Ulrik spend time with each other, neither is keen to make public the location of the gateway. After all, it's not easy getting dates when your father is King.
Ulrik of Mallenvaar is having problems of his own. Unlike Arianna, his father is not overly keen to announce him as his heir, not with his cousin fighting him for that position.
With treachery and trouble stalking them all, can they maintain the peace in both the Second and Fourth Realms?