Sarah Jane has to make a devastating sacrifice in order to save Earth from the Trickster.

Now hunted by the Bane, Mrs Wormwood needs Sarah Jane's help to foil their plan to take over the galaxy with an ancient alien power. And Sarah Jane also needs help - from Sir Alistair Lethbridge-Stewart.

Luke is kidnapped by Mrs Wormwood and Kaagh. Sarah Jane prepares for a showdown at a stone circle.