dr who christmas episode, can someone explain something tomme plese?

[stitch]

why ws the empress awoken now? if her kids have been hibernating at the centre of the earrth for 4.6 billion years, then why ws she woken up now? ws it because of the hole? who dug the hole to the centre of the earth? i just didnt understand that.

i reckon it took her that long to get the hole dug....plus if she'd have decided to wake up her kids at any other time of year it wouldnt have made a good christmas story what with the star shaped spaceship, killer santas etc...! lol

do spiders dig?

Or was it something to do with finding the eejit to help her?
I wish my children would sleep for 4.6 billion years sometimes.....