The Forty Rules of Love by Elif Shafak
This novel intertwines two parallel narratives, one set in the 13th century and one in the modern day. The contemporary story follows a discontented American housewife who, while working as a reader for a literary agency, comes across a novel about the 13th-century poet Rumi and his spiritual mentor, Shams of Tabriz. As she delves into their story, she uncovers Shams' forty rules of love and begins to question her own life and relationships. The historical narrative, on the other hand, explores the transformative friendship between Rumi and Shams, and how their bond revolutionized Rumi's poetry and outlook on life.