My father-in-law died unexpectedly on the last day of the decade. He was a quiet, gentle man who had affected my husband’s and my lives more and more the older we became. We were devastated, and I felt guilty.

In 2008, after a trip to Kenya with my parents-in-law, I had begun a novel loosely based on the migration story of their family, in which each of the last three generations grew up on a different continent. My husband’s grandparents were from Gujarat, India, and immigrated to Nairobi—another corner of the British Empire—as teenagers. My Nairobi-born parents-in-law moved to the United States as a newly married couple. My husband was born in Wichita and grew up in Minneapolis. In my own Jewish-European family, I have to go back five generations to find someone born outside of the U.S., so I was fascinated by the dramatic movements and decisions of the family I’d married into.

In fiction, you build characters around a few important traits and pieces of biographical data. Personalities are expressed and tensions ratcheted through events large and small, lined up like mile markers on the highway. I knew