After we witnessed the wanton sex god that is David Mitchell tracking down his Scottish ancestry, Who Do You Think You Are are simmering things down a bit this week with Sex and the Cit's Kim Cattrall. She visits her birthplace of Liverpool to try to solve the mystery of her grandfather, who walked out on his wife and three daughters, never to be seen again. Kim's mother and her sisters don't even know what their father looked like. In the only picture they have of George, he is an indistinct shape peering out from behind a curtain. Problems. They are desperate to know what happened to their father. With no clues about the man apart from a newspaper article from the 1980s, the actor turns detective and follows a trail that leads to a painful truth.