Two Brains, One Skull - Separating Conjoined Twins

Safa and Marwa are twin girls who were born joined at the head. They were brought, by their family, from Pakistan to London's Great Ormond Street Children's Hospital for a series of highly complex operations to separate them. The BBC's Fergus Walsh has followed them through the dangerous nine months process aimed at giving independence to the girls, who've never been able to see each other's faces.