The twins who share a brain.

This documentary looks into the world of Tatiana and Krista, conjoined twins living in Vernon, Canada. They are unusual, not just because they are joined at the head, a condition called craniopagus twins, but also because they are joined at the brain. Their mother, Felicia Simms, describes her pregnancy, the birth and the expectations for their life given that separation was not an option. Their mother believes that their shared thalamus means they think the same thoughts and can feel the same things as each other. The programme follows the family as doctors attempt to prove or disprove this possibility as well as tests which assess their health in general as Tatiana's heart is under pressure to keep the circulation going for both of them. They meet famous conjoined twins Lori and George Schappell who talk about how they have managed to live their lives conjoined at the head.