The Dark Ferryman — Jenna Rhodes

The Dark Ferryman is the second novel in the spellbinding fantasy epic, The Elven Ways.  

Kerith is a land bereft of magic since the devastating Magi Wars. Warlike Galdarkans, peaceful Dwellers, Kernan tradesmen and merchants, and brutish Bolgers have co-existed since that time, until the Vaelinars mysteriously appeared from nowhere, bringing with them a different sort of elemental magic. Now, generations after their arrival, Kerith stands at a turning point.
 
As hostilities escalate, and treachery abounds, Rivergrace and Sevryn -- she a Vaelinar raised by a loving Dweller family, and he an orphaned half-breed who has served Lariel, the Vaelinar Warrior Queen, faithfully for many years -- are accused of traitorous acts and are forced to follow separate paths in search of their destinies.
 
Yet both keep encountering the Dark Ferryman, the most mysterious of all the magically-created passages of power known as the Vaelinar Ways. And neither knows what payment the Ferryman will demand for the aid being given them....