Monsters from the skies terrorise the Sunder Mountains in the north, stealing the bravest and strongest warriors of the Mountain Men tribes, shattering the peace Navarr and Mizzell had found in The Glade. When they go to investigate, both are swept up into the mystery surrounding the Slavers from the South.

Meanwhile, the crew of the Cornwallis eke out an existence in the deserts south of the border. Framed for murder and their ship hijacked, the crew must escape through the deserts, and attempt to rescue their crew from the Great Slave Markets.