The Dragon's Queen: A Dragon Shifter Romance (Falling For a Dragon Book 5) - Falling For a Dragon, #5

Kate and Ros' final adventure takes them to the ends of the world as they dig deep into the world's past to decipher the problems of the present. Their destination is the fabled city of Baheal, a city so old it was lost long before the Pactus were created, but first they have to find the location. That isn't an easy matter when every ship on the high seas refuses to take them past the dark shadows that surround Umbria, the kingdom of their nemesis, Corvinus.
The machinations of the King of Shadows work against them, thwarting their every move as they try to pass over the rough and uncharted western seas. An old friend comes to their aid, and on the waves they discover that Kate has come away from the adventure in the capital city of Cunabourne with a few changes. The goddess' words ring in her mind as they near the end of their odyssey, and she begins to wonder if she'll return as herself, or something else.
With Ros at her side and the future ahead uncertain, they face their greatest trials with one thing certain. If one falls, they both fall.