The Doctor attempts to prevent the destruction of an unmanned spaceship with a cargo of dinosaurs alongside Amy, Rory, Rory's father Brian, Queen Nefertiti, and big-game hunter John Riddell.
After the intense drama of episode 1 (Asylum of the Daleks), Steven Moffat decided to go with a light hearted, action oriented adventure. At least for the majority of the episode. Imagine the reaction if "Raiders of the Lost Ark" had ended with Indiana Jones going down a dark path. This Doctor, similar to what happened to the tenth Doctor, is experiencing a loss of his moral center without a full time companion.
While Queen Nefertiti and John Riddell were good additions to the cast, Rory's father stole the show. One of my favorite scenes was the first meeting between him and the Doctor.
What themes do we see continued from the first to the second episode? Death. In one case we see the death of a planet, in the other the death of a race. It appears that Moffat is laying the groundwork for episode five. Five will be the final episode for Amy and Rory. The villain of that story will be the Weeping Angels.