An obvious time travel story. Rose attempts to change time, attempts to save her Father and stop him dying. Has some nice touches and good characterisations. I do not know why this has not occurred to any previous companion. Clearly anyone who can travel in time must have something in their past that they may want to change/correct. I do not like the creatures, to my mind the perils of changing time could have been highlighted without creating stupid flying creatures. How does having them work? Surely if they kill lots of humans at random then it is creating more and more changes in time.