It 's Doctor Who , anyone can come back , anything can be undone , if Rose can come back from another dimension , the Master can survive the Time War and the Daleks can keep escaping certain extinction ... they can get around this plot point should it ever serve them .
According to the above context, answer the following question.
what is the reason anyone can come back and anything can be done ?


Doctor who is a fictional story where time travel and almost anything else is possible .