A big black question mark is creeping across Spain, shaking and shocking a growing number of mothers and fathers of still-born babies and prompting them to dramatically rethink the fate of their children. Did they really die or were they sold to other families in a macabre, callous and widespread black-market trade that's only recently been uncovered? And stepping into this murky saga is an apparent foreigner who was one of those stolen and sold and who's only now returning to his real birthplace in search of his natural mother and the truth.