...Raoul Wallenberg was a minor official of a neutral country, with an unimposing appearance and gentle manner. Recruited and financed by the U.S., he was sent into Hungary to save Jews. He bullied, bluffed and bribed powerful Nazis to prevent the deportation of 20,000 Hungarian Jews to concentration camps, and averted the massacre of 70,000 more people in Budapest's ghetto by threatening to have the Nazi commander hanged as a war criminal.

Then, on Jan. 17, 1945, days after the Soviets moved into Budapest, the 32-year-old Wallenberg and his Hungarian driver, Vilmos Langfelder, drove off under a Russian security escort, and vanished forever.

And because he was a rare flicker of humanity in the man-made hell of the Holocaust, the world has celebrated him ever since. Streets have been named after him and his face has been on postage stamps. And researchers have wrestled with two enduring mysteries: Why was Wallenberg arrested, and did he really die in Soviet custody in 1947?

Researchers have sifted through hundreds of purported sightings of Wallenberg into the 1980s, right down to plotting his movements from cell to cell while in custody. And fresh documents are to become public which might cast light on another puzzle: Whether Wallenberg was connected, directly or indirectly, to a super-secret wartime U.S. intelligence agency known as "the Pond," operating as World War II was drawing to a close and the Soviets were growing increasingly suspicious of Western intentions in eastern Europe...