The Doctor and Leela find themselves in the middle of London at the time of a new energy crisis. The GlobeSphere Corporation seems to have all the answers — but several thousand protesters beg to differ. What is the connection between the National Gallery and a base on the Moon? Has radical thinker Damien Stephens simply sold out, or does he have a more sinister agenda? The Doctor has detected a mysterious energy reading. Could it be that the most evil creatures in the universe have returned to claim ultimate victory once and for all?