The Beast Below

For Amy Pond's first trip in the TARDIS, the Eleventh Doctor brings his new companion to the 33rd century, where all of the United Kingdom's citizens (apart from the Scottish) live onboard Starship UK, searching for a new home amongst the stars as the Earth is being roasted by solar flares. However, the Doctor soon finds something amiss onboard the vessel. The citizens appear to fear "the smiling fellows in the booths" and ignore crying children. What is going on? What secrets does Starship UK hold at its depths, and who is hiding them? Soon, the Doctor is forced to make an impossible choice. No matter what he chooses, death is the only outcome.