It's day two of Rebecca's marathon of show-watching in Edinburgh for 'The Sick of the Fringe', a Wellcome Trust project looking at the medical, psychological and mental health themes behind some of the performances. In today's podcast, hear her talk introversion with fans of comedian Sofie Hagen, as well as reflecting on a shocking neurological sci-fi play called Grey Matter - plus obviously revealing how many steps she did. But who is tonight's mystery celebrity spot?