"Conor Broekhart was born to fly. . . ." Raised on the diamond-rich Saltee Islands under the beneficence of a generous king, Conor dreams of building and flying the first heavier-than-air machine. With the help of his brilliant tutor, who instructs him in swordplay and aeronautics, he begins to design such a craft. Then the power-hungry Marshall Bonvilain, commander of the Saltee army, commits a pair of murders that threaten to destroy Conor's dreams of flight . . . and his life.