Ocean in every 100,000 births, parents and doctors are presented with one of natures greatest challenges. Twins are born, to joined together. What causes twins to be born this way? What can Doctors do to help them? And what are the prospects for spend their lives joined together? This documentary, filmed in the USA, South Africa, Russia and Poland, tells the story of some of the most dramatic recent separations of conjoined twin babies - and interviews adult twins who remained conjoined.