This episode was the final story to take place before the big two part season finale. Danny Pink has more of a role in this episode. Clara and Danny have taken a group of schoolchildren to a museum for a sleep-over. It seems, however, that a strange phenomenon has occurred over night; the opening scenes show a schoolgirl running through a forest and knocking on the door of the TARDIS, apparently looking for the Doctor.
Soon enough, Clara and the Doctor cross paths. Danny wants answers, as Clara had previously told him she hadn’t seen the Doctor for quite a while. Her lies soon unravel alongside the mystery of why London has been over run by trees.
The child characters in the story are featured a lot, which at times can be annoying. Although, the story of the trees is actually quite an interesting one. It seems they are here to protect us, as a solar storm is coming to Earth. One of the children is given a back-story; her sister had gone missing and she is now a troubled child. Could there be a connection? The Doctor appears a bit grumpy having the children in the TARDIS, which is quite amusing.
Danny and Clara have their little chat, as the end of the world could be near. Danny starts to realise that Clara needs the Doctor. Clara believes that the Doctor could save the day, and with a little help from the children and the trees the Earth is saved. For some unexplained reason the little girl’s sister also returns (this part is a bit of a mystery).
The story was beautifully written and the pace was good. In places though, the back story of the little girl and her missing sister seemed to be mashed in to the overall plot, and the return of the sister seemed to happen with no real explanation. I felt almost like we needed another episode before this one to explain the disappearance.
Apart from the final two episodes, the rest of the season has been made up of stand-alone episodes. I do feel that some of the stories told this series could have been done better as two-parters. Towards the end of this episode, Clara does seem to realise that maybe she should settle with Danny and stop travelling with the Doctor, but I wonder, will this be a simple choice or will something get in the way?