Five years after the 1965 capture of Adolf Eichmann in Buenos Aires, one of his Mossad abductors was sent back to South America to kill another fugitive Nazi, the so-called "butcher of Riga," Latvian Herberts Cukurs. Researching the case, Linda Kinstler discovered that her grandfather, Boris, had served in Cukurs's killing unit and was rumored to be a double agent for the KGB. As Kinstler recounts here, the information she uncovered might have resulted in Cukurs's pardon, at the precise moment that the last legal witnesses were dying.