with the battle over, the doctor explains that the radiation from the weapon was what was killing their crops but this limiting factor has now been removed. earth has agreed to send a real adjudicator to uxarieus, and caldwell has decided to join the colonists. he tells them that he can help them with their power supply. the doctor and jo return to the tardis, which returns to unit headquarters mere seconds after it left. having accomplished what the time lords intended, the doctor is once again trapped on earth.