Albert Einstein was on the run and already fearful for Germany's future more than a decade before the Nazis seized power in his country, according to a previously unknown letter, brought forward by an anonymous collector.
The Associated Press got a glimpse of the letter, which is set to go on auction next week in Jerusalem. The opening asking price is $12,000.
The letter dates back to August 1922 -- Einstein's longtime friend and fellow Jew, German Foreign Minister Walther Rathenau, had just been assassinated and police had warned the noted physicist his life could be in danger too.
So Einstein fled Berlin and went into hiding in northern Germany. From there, he wrote the letter to his beloved younger sister, Maja, warning of the dangers of growing anti-Semitism.