David Tennant is a Scottish actor who has starred on stage, screen, TV and radio. In 2008 he played a widely praised Hamlet for the Royal Shakespeare Company but is probably best known for his role as the tenth incarnation of the Doctor in Doctor Who, along with the title role in the 2005 TV serial Casanova and as Barty Crouch, Jr. in the 2005 film adaptation, Harry Potter and the Goblet of Fire.
Katie Thistleton is a children's TV and radio presenter who is passionate about raising mental health awareness through her role as a celebrity ambassador for the mental health charity Mind and an ambassador for the children's mental health charity Place 2 Be. Katie trained as a journalist after attaining a degree in English and Creative Writing and has worked for the BBC ever since, initially behind the camera, then moving in front of it. She lives in Manchester.