TV presenter Kate Humble knows little about her family history. What she does know is that her paternal grandfather was a test pilot, and she believes her maternal grandfather ended up in Colditz. On the trail of her grandfather Bill Humble, who was a test pilot during the Second World War, Kate visits the RAF Museum. She is astonished to discover what a legend Bill was in flying circles, and is amazed to see his daredevil flying for herself in archive film held there.