Lance and Quill - Falcon Chronicle, #2.5

The greatest traitor may be her heart. One man will die, one man will rise, and one girl will change the Araby sands forever. Alaina flees the wazir's rose perfume and court gardens to seek refuge with a prince of the sands. Foiled in her desire to rise as a renowned scribe in the court of the Caliph, Alaina finds herself tending an ailing sheik, disguised as an apprentice healer to an exiled warrior.
But the prince pierces her deception, and soon has her scribing for him. Struggling to be worthy of his grandfather's seat as sheik, Prince Faisal has enemies Alaina would gladly shield him from. But she must keep her identity hidden from the tribe, even as she faces Faisal's rival. Falling in love with a prince she is not worthy of, Alaina falls yet again to his rival's cunning schemes. For a traitor lurks in the Oasis of Oaths.
When the wazir's Hand discovers them and enemies converge, Alaina must rise and break the webs of deceit. If she can discern her uncertain heart before it is too late. Will the girl who desired a scribe's cushion in the caliph's court find richer things than rosewater and immortal poetry in the desert sands?