Doctor Who: Harvest of Time

After billions of years
of imprisonment, the vicious Sild have broken out of confinement. From a
ruined world at the end of time, they make preparations to conquer the
past, with the ultimate goal of rewriting history. But to achieve their
aims they will need to enslave an intellect greater than their own...
On
Earth, UNIT is called in to investigate a mysterious incident on a
North Sea drilling platform. The Doctor believes something is afoot, and
no sooner has the investigation begun when something even stranger