Tannis threatens to shoot either the Doctor or Antimony if they move. He then reveals his secret — he is a Time Lord — but unlike the Doctor or the Minister, one who wants to use his powers to rule the Universe. The Doctor tells Antimony to flee, but he refuses. Tannis says that this is because Antimony, without realising it, considers the Doctor to be his father. He then shoots Antimony in the leg, revealing circuits and servo-mechanisms. Having seen so many companions leave or die, the Doctor built a companion who would always stay with him. To the Doctor's dismay and helplessness, Tannis taunts him saying the Doctor could save Antimony by speaking Tannis out of existence, but that he won't do it. Finally, Tannis shoots Antimony in the head, and leaves the Doctor to watch him die.