Pillars for the Gods - Laura Chamberlain JK

As Ethan treks across the Persian Empire in search of his older brother, he crosses path with an injured man who needs help, but his innocent act of help leads him to the court of Halicarnassus. The district ruler, Mausolus, sees something useful in Ethan and his life explodes with intrigue and excitement, unimaginable experience and incredible opportunity. But an assassin remains at large and Artemisia, Mausolus' queen, has grand ambitions for her legacy that may threaten the safety of the whole city.