LONDON – Hiding in plain sight beside a row of London 2012 shuttle buses stands a small metal frame holding the mystery of a past Olympics. Attached to the frame is a photograph. It is an old photograph, snapped on an August afternoon during the 1936 Olympics in Berlin.
And in this picture there is a woman, dressed in the white uniform of the German team. She is standing on a medal podium having just received her silver for fencing and her right arm is outstretched in a Nazi salute.
The woman's name is Helene Mayer.
She is the daughter of a Jewish man.
And because of this fact, she has essentially been banished from Germany to the United States, allowed on the Olympic team only so the Nazis can tell the world they support a Jewish athlete.
At best she is a pawn. At worst she is scorned.
Still, when she wins a medal, she raises her arm.
[ Related: American under fire for carrying Mexican flag ]
The frame holding Helene Mayer's photo stands in front of the Wiener Library for the study of the Holocaust and Genocide. The library is located on London's Russell Square where thousands of fans and journalists rush to catch double-decker shuttles to the Olympics, never noticing the photo on the Wiener Library's steps.
The photo advertises an exhibit inside on the Berlin Olympics and once through the door and into a tiny room in the front, the walls are filled with photos of Jesse Owens, photos of the stadium, photos of men jumping and photos of swastikas, all pulled from the library's archives.
Yet the most compelling image is that of Helene Mayer. Her face is determined. Her posture is perfect. Her arm points strong and fierce. She leaves no doubt as to what she is doing. It is such a powerful photo – both beautiful and awful – that Bridget McGing, the Wiener's development director, says it all but leaped at the library executives who put together the exhibit.
"It appears to tell you one thing but with a little bit of history it says something totally different," McGing says.
And it leaves everybody who sees it struggling for the same answer.
"One of the great mysteries is why she did what she did," says Anton Rippon, a British writer and the author of the book "Hitler's Olympics."
Most accounts of Mayer's life say she did not consider herself Jewish. Her mother was not Jewish and Mayer and her brothers were not raised Jewish. But the Nazis didn't seem to care. Her father was Jewish and so she was seen as a Jew.
So why would she salute Hitler?
Historians tend to believe that Mayer, who died in 1961, missed her home. Her mother was ill and she wanted to see her. Some books on the 1936 Olympics suggest she wanted to be granted full citizenship, something that had been taken away from many Jews. In many ways, she just wanted to be German.
In simpler times Mayer had been Germany's best fencer. When she was 17 she won a gold medal at the 1928 Olympics in Amsterdam. Four years later, she finished fifth in Los Angeles. Accounts suggest her poor performance in the 1932 Games was due to illness, others say she was distraught over the death of her boyfriend who was in the German Army. She stayed in Southern California to go to school, hoping to someday become a German diplomat.
But already there were signs she did not have a future in her homeland. In 1933 she was expelled from the prestigious Offenback Fencing Club because of her Jewish heritage, which meant even if she did return to Germany she wouldn't have a place to train. Still she hoped to compete for Germany in her country's games. And for months before the Berlin Olympics, the German government played with those emotions, at times letting her believe she was welcome, then going silent. Eventually she and a Jewish high jumper named Gretel Bergmann were put on the team. Right before the Olympics, Bergmann was told only two of the three German high jumpers would compete in Berlin and she was dropped from the Olympics.
Mayer, however, was allowed to compete.
"I suppose one's overriding opinion is that it was an incredibly selfish thing to do, to go back to Germany," Rippon says.
Back in the U.S., Mayer faced strong pressure to stay away from Berlin. Several Jewish writers and advocates urged her to stay in California. When she announced she would compete, her decision to compete for Germany was heavily criticized. She went anyway.
[ Related: Which athletes left London in disgrace? ]
Rippon's book says Mayer competed wearing the Nazi swastika on her uniform. It also pushes the idea she used the opportunity to see her mother "and strike a blow of Jewish athletes." Other accounts are less clear as to her intentions.
Perhaps the best explanation came in a letter she wrote to her German teammates a few months after the Olympics, long after she had returned to California. The letter was reprinted in the book "Nazi Games" by David Clay Large.
"Here in America the press has made the [German] Olympics look extra bad," she wrote toward the bottom of the letter. "Nothing but propaganda against Germany! So I guess it didn't help much that all of us, and by this I mean also the American competitors, worked against this propaganda.
"Will we see each other again in the future? I don't know. I know that I'd like to return to Germany, but there's no place for me there now… I belong to that part of humanity that has been hard hit in bitter fate. I love Germany every bit as much as you do and I feel as German as you!"
Eventually Mayer would return to Germany in 1953 and die later on that year. She was only 53. And with her death went the answers to something that has baffled those who have seen the picture of that August day. Like many of the descriptions of her life, there is a disparity of opinion on her feelings about doing the Nazi salute.
Some say she regretted competing for Germany and stretching her arm. Others indicate she felt it was necessary to do.
"If it were not for the fact that the Olympics were being held in Berlin would she have gone?" Rippon asks. "It's an interesting question."
Standing on the steps of the Wiener Library and staring at Mayer's arm, stretched straight, with so much purpose, the answer seems forever lost.
More Olympics coverage on Yahoo! Sports: