Prof. Yair Tauman is haunted by a childhood memory which never leaves him - the parting from his sister Tikva, who, on the day of her departure for the United States, learns that she is adopted. Born in Lithuania, she was given to a Christian family that hid her for the duration of the war. For some years she lived with the Tauman family in Israel, and then was separated from them without properly understanding why. She was sent to the US, from where she sent letters to her brother Yair, and he in turn sent letters to her. She continued to live in America, but the letters eventually stopped. Nonetheless, Tauman...