For more than 50 years, Herman Wouk has dreamed of writing a novel about the life of Moses Finally, at the age of 96, he has found an ingeniously witty way to tell the tale of The Lawgiver, a romantic and suspenseful epistolary novel about a group of people trying to make a movie about Moses in the present day. At its centre is Margo Solovei, a brilliant young writer-director who has rejected her father's strict Jewish upbringing to pursue a career in the arts. When an Australian multi-billionaire promises to finance a movie about Moses, Margo does everything she can to land the job, including a reunion with her estranged first love, an influential lawyer with whom she has unfinished business.

The year is 1031. Karimah, a charming, headstrong Jewish nineteen-year-old has followed her heart on an adventure that will take her far from home. The story is revealed in her letters to the family she left behind in Egypt, their letters to her, and their correspondence with others as they seek to make sense of the disorder that Karimah has brought to their lives. Details of everday life from a millennium ago are now familiar to scholars through the discovery of the Cairo Geniza, a synagogue storeroom full of several centuries' worth of religious manuscripts, receipts, and business correspondence. The author creates an impassioned portrayal of a time when Jews and Muslims lived together in reasonable harmony.