 She would not become directly involved in the Wallenberg case until October 1989, after Soviet authorities returned Wallenberg's possessions to his next-of-kin, acknowledging their “tragic mistake,” but failing to present any evidence of his death.At this point, Mesinai states, she committed herself to the task of ascertaining Wallenberg's fate “beyond reasonable doubt.”

In 1991, Mesinai and Mikhail Kazachkov, a recently released Soviet prisoner, created the Ark Project, dedicated to enforcing “rule of law” in the case of foreign prisoners in the Gulag.Kazachkov and Mesinai initiated a trans-Russia appeal for information regarding missing American prisoners of war, both through publication in the human rights press and radio networking.