Jerusalem, 1192. The Third Crusade rages on. Rahma al-Hud loyally followed her elder sister Zeena into the war over the Holy Land, but now that the Faranji invaders have gotten reinforcements from Richard the Lionheart, all she wants to do is get herself and her sister home alive.

But Zeena, a soldier of honor at heart, refuses to give up the fight while Jerusalem remains in danger of falling back into the hands of the false Queen Isabella. And so, Rahma has no choice but to take on one final mission with her sister.

On their journey to Jerusalem, Rahma and Zeena come across a motley collection of fellow travelers—including a kind-hearted Mongolian warrior, an eccentric Andalusian scientist, a frustratingly handsome spy with a connection to Rahma's childhood, and an unfortunate English chaplain abandoned behind enemy lines. The teens all find solace, purpose and camaraderie—as well as a healthy bit of mischief—in each other's company.

But their travels soon bring them into the orbit of Queen Isabella herself, whose plans to re-seize power in Jerusalem would only guarantee further war and strife in the Holy Land for years to come. And so it falls to the merry band of misfits to use every scrap of cunning and wit (and not a small amount of thievery) to foil the usurper queen and perhaps finally restore peace to the land.