The Pandorica Alliance was a large and possibly uncountable number of aliens who are all of The Doctor's enemies (excluding the Judoon), formed an alliance to stop the greatest threat in the universe, which they all believed to be the Doctor. They predicted and calculated that an explosion of the TARDIS would cause the cracks in time that were dangerous to all of the members, alongside the rest of the universe, and other universes. They came up with a plan to trap the Doctor and to bring him to the Pandorica where they then imprisoned him inside it. As they knew that the cracks would be caused by the explosion of the TARDIS, they sealed the Doctor inside to prevent him from doing so, however, they did not know that River Song one of the Doctor's companions could fly the TARDIS as well.