Amy, Rory, and River talk at a diner when they discover the fourth envelope was sent to the Doctor, alive and 200 years younger than the one at the lake. The Doctor’s companions tell him about space 1969 and Canton, but refuse to tell him about his death or that the sender is the Doctor himself. The Doctor and his companions travel back to 8 April 1969, where the younger Canton, a former FBI operative, is briefed by President Richard Nixon about a series of phone calls Nixon received from a young girl asking for help. The Doctor arrives in Washington, DC and convinces Nixon to give him a few minutes to locate the girl. Based on the phone call and the girl’s mention of a “spaceman”, he tracks down the Florida intersection the girl where is located. Meanwhile, Amy meets and takes a photograph of one of the leaders of the Silence, a group she also saw by the lake which people forget about any time someone stops looking at them.
It's hard not to like Sagittarians, for their openness, generosity, and sociable nature. They are deep thinkers in search of universal wisdom, attracting them to philosophy and religion. Their minds can grasp both the details and the bigger picture: they can think with intellectual precision but also intuitively. That unusual combination of thinking skills allows them to be at the forefront of creative ideas. They are idealistic and care about the state of the world, leading them to take up vocations in medicine, education, religion, and politics. They need to be highly independent in their work and in their personal lives.
As time passed, the region would have cooled down considerably and contracted--thus pulling away from its surroundings and forming fractures akin to the cracks that form in mud as it becomes dry--but on a considerably larger scale.
These icy moon-worlds are the next important step in the scientific quest for the Holy Grail of life beyond our own planet. It is a strange era in human history. Astronomers have collected large amounts of data revealing bewitching clues that habitable ocean moon-worlds may be out there, within the family of our very own Star. Humanity is poised at the beginning of a new era. Sophisticated new technology might very soon answer the profound, and very ancient question, "Are we alone?"