Donna and the Doctor land on Earth but everything seems to be perfectly normal. Suddenly there is something like an earthquake and when the Doctor looks outside the doors of the Tardis, the Earth is gone. It has been moved to a place unknown to the Doctor. To find it again, he seeks out the Shadow Proclamation with Donna to ask for help. Meanwhile on Earth, the people are terrified because there are suddenly strange planets in the sky and they don't know why. UNIT, Torchwood and Sarah Jane Smith try to find out what has happened when their darkest fears come back in form of the Daleks. Martha tries to call the Doctor but he doesn't respond and when the Daleks attack she manages to return to the UK with an experimental teleportation device. Harriet Jones brings Sarah Jane, Torchwood and Martha together and together they try to call the Doctor with the sub-wave network. The Doctor and Donna have received useful information at the Shadow Proclamation and are now in the Medusa Cascade but there is no trace of the missing planets. When the Doctor gets a call, he is able to link to the signal which brings him into the same time with the missing planets. Will he and his friends be able to defeat the Daleks?
I really think this is a great opener for the series finale. It just has such a mean cliffhanger that you have to watch the next episode when you want to know what happens. It's great that all of the companions of the Doctor fight together to defeat the Daleks and you wouldn't have expected that this would happen. That was a big surprise when they all appeared one after the other and there is even Harriet Jones one of my favourite characters although this is her last appearance on Doctor Who. The Daleks are always a good enemy for a series finale and with the return of Davros, the creator of the Daleks is back again. With the Earth under attack, the companions ready to fight for their lives and the tragic meeting of Rose and the Doctor, the story just begins. There will definitely be some great surprises in the last episode of series 4.