DOCTOR WHO IN DETAIL

The Doctor is showing Bill around the TARDIS. Nardole interrupts and tells the Doctor not to go offworld. The Doctor tells Nardole he is going to return to his office, and asks Nardole to make coffee. The Doctor then tells Bill they can take a trip and be back before the kettle has boiled. He asks Bill if she wants to go to the past or the future: She chooses future to see if it is happy.

On the planet of one of the first human colonies Kezzia is in a wheat field with a robot. When she returns to the colony she is told that there is a problem with the Vardies (tiny air borne robots) and that she needs to keep smiling - even when her sister tells her that her family, and more people, are dead. Kezzia doesn'tr smile - and is killed by the Vardies.

When the TARDIS arrives the Doctor and Bill find a colony devoid of human life. Being Bill's first new planet she is keen on taking pictures on her phone. As they walk around the colony something hits Bill and the Doctor and their ears are upgraded: Bill can now hear the Doctor inside ears, as though through an ear piece. Although there appears to be no life they do come across a basic robot that acts as an interface to the main robots - the Vardies. The robot offers Bill and the Doctor a badge each that shows their current mood. When attached the badge disappears and re-appears on their backs.

The Doctor's first thought is that humans have sent robots ahead to build the colony so it is ready for when they arrive. Until he finds a necklace on the floor. But there should be at least a skeleton crew. In a garden being fed by calcium fertiliser the Doctor finds the remains of the skeleton crew. This makes the Doctor and Bill upset, and their mood is reflected by one of the robots. The Doctor and Bill run, but are trpped at a crossroads by robots. The Doctor realises if they smile it makes their mood badges happy, which in turn makes the robots happy, allowing the Doctor and Bill to walk past them.

Walking around the Doctor comes to realise the colony was not built by the Vardies - they became the colony, and that the whole complex is made up of the microbots. But when the first colonists arrived they would have lived in their ship and built outwards. After a bit more searching the Doctor and Bill find the original ship. Inside the ship is a map. The Doctor leaves Bill so she can direct him to the engine room using their 'earpiece' upgraded ears so he can destroy the colony.

The Doctor finds the cold fusion reactor inside the engine room. It would be easy to destroy - almost as though it wanted to be blown up. When Bill finally thinks of photographing the map so that she can go with the Doctor she realises he has already memorised the map, and is trying to keep her out of trouble.

On her way to find the Doctor Bill finds a room containing a dead body that has an active mood badge on it. At the foot of the body is a tablet that contains details of Earth history. As she is about to leave she finds a small boy. The boy takes the Doctor and Bill to a room containing hundreds of pods - containing the new colonists. THe process for waking them started when the Doctor and Bill entered the ship. They return to the engine room to stop the explosion. In the pod room a colonist has awoken.

Bill shows the Doctor the tablet she found - and the body. The Doctor comes to realise that after the woman died other crew members experienced grief. The Vardies were supposed to ensure people were happy. As the grieving people were not happy they were killed to stop making other people unhappy. The Doctor tries to explain this to the colonists who are waking, and they start to arm themselves. When one of the colonists shoot a robot the Vardies come out of the walls and attack.

Using the sonic screwdriver and broken robot the Doctor is able to basically turn the Vardies and robots off and on again - resetting them.