Ever since Dorian Maldovar mentioned it in Series 6, Trenzalore has managed to be a crucial, yet still mysterious part of The Doctor's legacy. We know it's where he's supposed to die, we know he's technically (or advisedly) not supposed to go there, and we've seen his grave amidst its barren wastes in The Name of The Doctor. Apparently we've gotten a little bit ahead of ourselves though, as the events of The Time of The Doctor precede those of The Name of The Doctor. Trenzalore is still populated and described as a "backwater" planet. So a backwater planet with an unsuspecting population... and somehow a woman with Dalek modifications and an Army wants to seize it? What's so important about Trenzalore, besides the prophecy of The Doctor's death? Why is it important enough to be used as a trap to lure The Doctor, and why is it so central to the plan that pretty much every villain you saw in The Pandorica Open has decided to reunite? Well, if there's going to be a multitude of villains and a death toll in the millions, there's only one explanation: there's something on that planet that they want. Whether it's a resource or a person, there's something down there that everyone's interested in possessing.