 The first part, "Human Nature", aired one week prior, on 26 May.In the episode, aliens called the Family of Blood attack an English boarding school and its surrounding village in 1913 to seek a fob watch which contains the essence of the long-lived alien time traveller the Tenth Doctor (David Tennant).In a "Doctor Who Magazine" interview, Executive Producer Russell T Davies characterised the "Human Nature"/"Family of Blood" two-parter as perhaps being too dark for the programme's audience.