The Doctor, Liv and Molly arrive back on Earth in the 1970s to investigate the Ides Institute. The timelines have shifted since the Doctor and Molly first travelled here and all is not as it was. Dr Sally Armstrong is still working for the Ides, but her associate has a devastating plan in mind.

Soon, Molly's 'dark eyes' prove to be at the centre of a plot to seize control of all life in the universe.