In the years before the First World War, a man called James Young Deer was celebrated in the American movie business papers as the world's first Native American film-maker.
He turned the conventions of the Western on their heads.
He showed Indian men rescuing, and marrying, white women.
In one film, 'The Squawman's Revenge', he presented audiences with a white man joining an Indian community - and helping them wreak vengeance on a white settlement.
Another of his movies was titled 'Red Eagle the Lawyer'.
Together with his wife, 'Princess Red Wing', Young Deer made dozens of movies like this, playing a key part in the earliest years of the California film industry.
But in 1914, faced with a sex scandal, he suddenly fled his job running Pathé's West Coast studio. He escaped to New York, and caught the boat to Liverpool.
Young Deer's work in California has recently become the subject of pioneering research in America. But the story of his time in England is unknown, even to most US historians of his work.
Now, with the help of specialists of the early British movie studios, film historian Matthew Sweet pieces together the astonishing story of how this extraordinary man spent much of 1914 shooting thrillers in London.
He visits the sites in Finchley, Waterloo and Crystal Palace where Young Deer shot a series of gangster flicks like 'The Queen of the London Counterfeiters' and 'The Black Cross Gang'.
Historian Gerry Turvey shows Matthew a breathless interview in the British movie press, revealing Young Deer's hair-raising zest for blowing things up.
And Matthew explores why, once he returned to America as war broke out, Young Deer's career never recovered.
He listens to a rare interview, conducted in the 1970s by film historian Kevin Brownlow, with Al Hoxie, a veteran of the early days of Hollywood. Hoxie recalls how Young Deer spent his later years running a two-bit acting school - forgotten by the industry for which he did so much.
Young Deer was accepted and promoted as a Native American, and his films were received as such at the time.
Yet, intriguingly, Matthew hears that there is now some doubt about his origins.
So he talks to Philip Deloria, a historian of Native American heritage, about what the legacy of Young Deer - radical movies, murky background and all - means today.
With Angela Aleiss, Andrew Brodie Smith, Kevin Brownlow, Ian Christie, Philp Deloria, Tony Fletcher and Gerry Turvey.
Producer - Phil Tinline.