Day of the Moon is the second episode of the sixth series of Doctor Who. It stars Matt Smith as The Eleventh Doctor, Karen Gillam as Amy Pond, Arthur Darvill as Rory Williams, Alex Kingston as River Song, Mark Sheppard as Canton Everett Delaware III, and Stuart Milligan as Richard Nixon.
The story starts several months after the last story ended, with The Doctor and his team scattered across the nation. The Doctor himself is locked up in Area 51, and his companions are being hunted down across the country. Canton Everett Delaware III has proved himself a double agent, and Amy and Rory are being hunted down, with strange hash marks covering their bodies. River Song jumps off of a building in Manhattan. Finally, Canton steps inside of the perfect prison that the Doctor is trapped in, and smirking, shows him the body bags of Amy and Rory, declaring that now the doctor is locked in a prison so tight that not even sound or light can escape. "Perfect" says the Doctor, removing his shackles as Amy and Rory get out of their body bags, and the TARDIS goes to pick up River as she falls. And then the Doctor goes to show them his master weapon, as they return to Florida to look at Apollo 11. Is Apollo 11 his weapon? No, that would be silly. His weapon is Neil Armstrong's foot. Roll titles.
Following up on the bizarre, epic "The Impossible Astronaut", the conclusion "Day of the Moon" continues the adventure, solving some, but not all of the mysteries. And the story just gets weirder and creepier. The Doctor explains to his companions (and the audience) about The Silence, aliens who are memory proof, so that the moment a person looks away, they forget ever having seen them. The Silence have been on earth for a while, and The Doctor must come up with a plan to conquer a foe that can hide anywhere. He also has to find out why President Nixon was getting phone calls from a small girl. And his companions have to find out what this all has to do with the assassination of the future Doctor in the last episode.
Confused yet? Well, you should be. There is so much going on in this episode that the presence of Richard Nixon as comedic relief, which should be noteworthy, hardly gets noticed.
There are three scenes that best capture this episode: one, as Amy Pond is investigating a gothic orphanage during a thunderstorm, she finds a room full of the Silence: but we only realize that when we see the lightning flash, showing that in a split second she has filled her face with tally marks: a sign that she have seen the Silence. But since she can't remember, from the audience doesn't get to see. The horror of the episode comes what is unseen, rather than from what is seen.
The second scene is where the Doctor reveals his plan for defeating the Silence. Since the Silence have the power of post-hypnotic suggestion, he takes a video of one taunting that humans should "kill us all on sight" and slips it into the transmission of the moon landing, instantly turning all humans who are watching, or will watch, the video, into a weapon to be used against the Silence. It is The Doctor at his most tricky and most grand, and it ties thematically into the episode: the moon is a symbol of reflection, so the Doctor uses the reflection of the Silence against them.
The third scene, the closing scene, is where we find out why Canton got kicked out of the FBI: Richard Nixon tells him that as a reward for saving humanity, he will reinstate him in the FBI. It seems that Canton just wanted to get married, and Richard Nixon is progressive enough to accept that he wants to marry a black person, until he finds out that black person is also a man. I think it is more thematically linked to the episode than at first might be apparent, because Canton has needed to be "silent" about his sexuality.
And so the episode ends, although we have the mystery of why the Doctor was shot on the beach, and also, whether or not Amy is pregnant...mysteries that will be solved as the series progresses.