05E12 - The Pandorica Opens

When an unknown Van Gogh painting is found in a house in France in World War II, it's pretty obvious who it's meant for. It's left to Prime Minister Winston Churchill to try and contact the Doctor and does so in a round about way via an imprisoned Dr. River Song. The work is called Pandorica Opens, the Pandorica being a mythical enclosure for the most dangerous thing in the universe. The Doctor soon finds themselves in Roman Britain where at Stonehenge they discover the fabled Pandorica. Rory, who was supposed to have been erased from time and never existed, is now a Roman soldier but Amy doesn't recognize him. River travels to the future in the TARDIS and discovers something important in Amy's room.