This episode addresses the fantasy of any person who has ever imagined the potential of time travel what if you could go back and change your own life? In this case, Rose goes back in time and saves her father's life, and so the world is different because of the survival of one ordinary man. The episode accomplishes so much in regard to character development and emotional appeal Rose gets to meet the father who died before she was old enough to remember him, but unfortunately everyone else suffers because of her indulgence. Their deaths come in the form of the Reapers, fascinating monsters who set out to destroy the paradox world created by Rose's actions (although where were the Reapers when the Eleventh Doctor was creating paradoxes left and right? Or when the Master turned the TARDIS into a paradox machine? Could be an intriguing concept for a new episode). It takes the heroism of Rose's father Pete to banish the Reapers and rid the world of the paradox. In doing so, he shows us the power in the actions of an ordinary person and the ultimate good they can accomplish. In Pete, we can see the courage and tenacity in Rose that the Doctor saw when he invited her to travel with him in the first place. Fantastic Quotes From The Doctor: "Your wish is my command. But be careful what you wish for." "I did it again. I picked another stupid ape. I should have known. It's not about showing you the universe. It never is. It's about the universe doing something for you."