 To promote the special , three prequels were released . The first was broadcast during the 2012 Children in Need telethon on 16 November 2012 , titled " The Great Detective " . The Silurian Madame Vastra , her human wife Jenny Flint , and the Sontaran Strax ( all returning from " A Good Man Goes to War " ) describe a number of strange phenomena to a shadowed fourth detective . The fourth detective reveals himself to be the Doctor , and tells the group that he has retired . 
 To promote the special , three prequels <a href='uninflect' title='1'><mark>were</mark></a> released . The first was broadcast during the 2012 Children in Need telethon on 16 November 2012 , titled " The Great Detective " . The Silurian Madame Vastra , her human wife Jenny Flint , and the Sontaran Strax ( all returning from " A Good Man <a href='uninflect' title='2'><mark>Goes</mark></a> to War " ) describe a number of strange phenomena to a shadowed fourth detective . The fourth detective <a href='uninflect' title='3'><mark>reveals</mark></a> himself to be the Doctor , and <a href='uninflect' title='4'><mark>tells</mark></a> the group that he <a href='been_done' title='5'><mark>has</mark></a> retired . 
To promote the special , three prequels was released . The first was broadcast during da 2012 Children in Need telethon on 16 November 2012 , titled " The Great Detective " . The Silurian Madame Vastra , her human wife Jenny Flint , and tdaSontaran Strax ( alll returning from " A Good Man Go to War " ) describe a number of strange phenomena to a shadowed fourth detective . Thdaourth detective reveal hisself to be thedactor , and tell the group dat he done retired .