Kill The Moon-A Review.

This isn't the first time the Time Lord has visited our nearest celestial neighbour. One of the Doctor's earliest lunar adventures was in the 1967 Troughton story The Moonbase. In that incarnation the Doctor squared off for his second encounter with the Cybermen.

In the 1969 Troughton adventure The Seeds Of Death  the Doctor had to once again  visit a scientific lunar base to thwart the plans of the Ice Warriors, who were sabotaging the T-Mat, a matter transfer device that  the world relied on.

During the Pertwee Era, the third Doctor was sent to a lunar penal colony in the story Frontier In Space but strictly speaking, the Moon was the main focus of this story. Now the point of mentioning these stories was to show how Kill The Moon was molded into that same style of adventure.

The Moon-2049 A.D.

Clara informs the Doctor that Courtney (Ellis George), the disruptive influence school girl previously seen throwing up inside the TARDIS at the end of the last story, The Caretaker, is feeling worthless and insecure and asks the Doctor to tell her she isn't.

After much petty bickering which simply translates as the the Doctor doesn't really do apologies, he asks how she'd like to be the first woman on the moon and then the three travellers are whisked off to the lunar surface. The TARDIS has materialised on board a space shuttle packed with nuclear explosives and are about to land on the moon.
They are discovered on board by astronauts Lundvik (Hermione Norris), Duke (Tony Osaba) and Henry (Phillip Nice).The astronauts are investigating why the  land mass of the moon is breaking up. A simple physics experiment with a yo yo by the Doctor shows the gravity on the moon has dramatically increased.

At a now deserted Mexican mining base the TARDIS crew and astronauts Lundvik and Duke go inside to restore the power while Hery investigates around the outside of the base. Inside the Doctor restores lights and power but Duke is killed by a giant spider. Courtney unwittingly kills it by squirting it with a spray detergent.
Because the detergent kills 99.9% of germs the Doctor realises they aren't spiders but bacteria which live on something enormous.
Outside the base Henry has found a spot where the intruders are entering but he is killed too when he tries to investigate further.

It's at this point in the story the show takes on a sinister tone, very reminiscent of the movie Alien, with close ups of Clara's face and the sounds of the spider scuttling around somewhere in the shadows. It's quite an effective part of the story and builds up the tension nicely.

The Moon Is An Egg.

Piecing things together, from seeing the dead Mexican crew preserved in webs and the screen shots of the deformed lunar land mass, the Doctor decrees that the moon is actually breaking apart. Courtney asks to go back to the TARDIS. Clara argues that the moon can't break apart in 2049 because she's been to the future and it's still there, the Doctor counters that the one she saw could have been a hologram. Meanwhile on Earth, the moon's disintergration is causing severe weather problems so a solution must be found soon.

 Investigating a crevice where  more of the moon has shaken loose they discover Henry's body. The Doctor is attacked by another of the spiders but the sunlight drives it off. The Doctor quickly drops into the crevice to take a sample and informs everyone that what he has in a specimen jar is actually amniotic fluid. The moon is actually an egg and the egg is now hatching.

Humanity's Decision. 

 The Doctor now tells Lundvik and Clara that they must choose what to do, destroy the hatching creature or let it live. Courtney, communicating by phone from the TARDIS insists she should be part of the choice too so the Doctor tells her how to bring the TARDIS to them. Once the TARDIS has arrived he leaves, saying that it's not his moon so he won't decide.

The Doctor has also pointed out to Clara that this point in history is in flux, one of those periods in time where things could go either way...the moon may or may not be destroyed. Clara and Courtney argue that the creature should live, that the destruction of the moon will only result in the Earth's hemispheres having a permanent high tide and low tide. Lundvig points out that the left over "egg" will rain down on Earth and will be worse than the collision that wiped out the Dinosaurs.

Lundvig is setting the bombs detonation countdown timer and contacts Earth control, in order to make the right choice she asks all the lights on Earth to remain on if they want to let the creature live or turn all the lights off if they want them to blow the creature up.
The lights on Earth slowly go out...
Lundvig is about to prime the bomb when both Clara and Courtney stop her, at that moment the Doctor returns and takes them all back to Earth to watch the creature hatch.

A New Life And A New Moon.

On a beach somewhere on Earth the travellers watch as the creature hatches, the remnants of the moon dispersing into harmless dust and the creature laying another egg/moon. 
The Doctor informs them that because humanity chose life their species will endure for millenia and he also points out to Courtney that she should feel special, knowing that she helped shape mankind's destiny.
 Back in their own time and with Courtney back at school, Clara rounds on the Doctor and shows her utter fury, saying that he can't simply visit Earth when he likes then leave major decisions that affect the time line up to others. She effectively  tells the Doctor to "get lost" and she never wants to see him again.

The Story-The Good And The Bad.

This story has far more tension and 'chill' factor than other stories in this Season. Without being bogged down in the relationship ups and downs of Clara and Danny Pink the story moves at a much brisker pace.
For the first time we really get to see Peter Capaldi's interpretation of the Doctor and he is both likable and the same time slightly frightening and untrustworthy. The concept of an ultimate win or loose choice is also handled well and for once in a long time, the Doctor lets humans decide their own fate.
  The problems in the story really stem from some bad companion choices. Courtney may be a disruptive influence and that does give the character some leeway for being slightly surly but instead she comes across as an obnoxious fifteen year old.
Another problem I had was going from Courtney being given travel sickness pills to be able to fly in the TARDIS, to her donning a spacesuit and walking on the moon like she's been doing it all her life.
Surely there would be some sense of fear?
It's hard to see how the Doctor/Clara relationship can continue to survive with the new Doctor showing us he isn't warm and fuzzy like Matt Smith but perhaps this will actually make for better character dialogue and interactions.
Overall, a better action/adventure story than the others that have proceeded it.