The Doctor and Clara next return to present day London, however things aren’t quite right-causing the Doctor’s exterior dimensions to shrink, pretty much getting the Doctor stuck in the ship’s interior dimension with no real ‘exit’ apart from passing small objects to Clara-like his sonic screwdriver.
Becoming “Doctor Oswald” for a day, she befriends a local graffiti artist, Rigby, who notes that several people are vanishing-but oddly, with images of their bodies ‘painted’ flatly on the wall.
Clara, still communicating with the Doctor although he’s stuck in the pocketed TARDIS, figures out it’s the work of 2-dimensional aliens, who are trying to break into three-dimensional space. He tries to broker peace, but unfortunately these aliens-who are crossing over into our plane of existence and starting to learn how to become more 3-dimensional-are not that interested. He also nearly gets flattened by a train, and briefly turns the tiny TARDIS into a “siege mode” cube.
Managing to fool the “boneless” aliens and siphon off their energy, the Doctor manages to restore the TARDIS to it’s regular size and send the aliens back to their home dimension.
Meanwhile, the mysterious Missy has been watching this adventure…saying that she chose Clara well…
In their next adventure, it’s still present day London. Although for some reason, trees have sprouted all over the world.
The Doctor befriends one of Clara’s students, Maebth, who is troubled after the disappearance of her sister, and learns that she is communicating with an alien species who have created the trees. It turns out that their goal is altruistic-the trees are to protect the Earth from a dangerous solar flare-which then strikes the Earth harmlessly.
Meanwhile, Missy continues to watch the events unfold….