To the untrained eye, Rosalind Franklin's Photo 51 was simply a grainy black-and-white image of dark marks scattered in a rough "X" shape. But to the eye of a trained scientist, it was a clear portrait of a DNA fiber taken with X-rays. And to young scientists James Watson and Francis Crick it helped answer a great mystery - how do organisms live, grow, develop, and survive, generation after generation? This simple picture would change the way scientists viewed life itself.