So in the mid-1980s, biographers found a batch of letters written between Einstein and his first wife Mileva Maric before they were married. The letters discuss a pregnancy and the birth of a daughter in 1902, whom the couple named Lieserl. This was the first time the public ever heard Einstein had a daughter; due to her illegitimacy, Lieserl had been kept secret. In the 1990s, Michele Zackheim went to war-torn Serbia (where Mileva was from) to try to find out what happened to that secret child.

The first part of the book is about Mileva: her family background, her life, her romance and marriage to Einstein, and the eventual collapse of that marriage. The couple was at one time deeply in love, but eventually their love died and Einstein treated her quite badly. After their divorce he married his cousin Elsa whom he had been having an affair with. The second part of the book is about the author’s search for Lieserl: interviewing members of the Maric family and others who had known Mileva, digging through old archives, etc.

I already knew what the ending would be because I looked at the Wikipedia entry for Einstein’s family and it has a section about Lieserl. But I really enjoyed the story of the search, the people Zackheim met along the way, the possible Lieserl candidates whose lives she examined looking for clues, etc. And I enjoyed learning about Mileva, who was a very intelligent person in her own right and who may have helped Einstein with some of his scientific work.