1960, New York City: College student Rita Klein is a pioneering woman in the new field of computer programming—until she unexpectedly becomes pregnant. At the Hudson Home for Unwed Mothers, social workers pressure her into surrendering her baby for adoption. Rita is struggling to get on with her life when she meets Jacob Nassy, a charming yet troubled man from the Netherlands who is traumatized by his childhood experience of being separated from his mother during the Holocaust. When Rita learns that Hitler’s Final Solution was organized using Hollerith punch-card computers, she sets out to find the answers that will help Jacob heal.

1941, The Hague: Cornelia Vogel is working as a punch-card operator at the Ministry of Information when a census of Holland’s population is ordered by the Germans. After the Ministry acquires a Hollerith computer made in America, Cornelia is tasked with translating its instructions from English into Dutch. She seeks help from her fascinating Jewish neighbor, Leah Blom, an unconventional young woman whose mother was born in New York. When Cornelia learns the census is being used to persecute Holland’s Jews, she risks everything to help Leah escape.

After Rita uncovers a connection between Cornelia Vogel and Jacob’s mother, long-buried secrets come to light. Will shocking revelations tear them apart, or will learning the truth about the past enable Rita and Jacob to face the future together?