The Doctor is missing and all aeroplanes have been suspended in mid-flight. Missy is trying to get attention and she wants Clara to join her in a lovely little square in one of Earth's "hot countries". They travel to mediaeval England with the help of Missy's vortex manipulator and find the Doctor throwing himself a party.
But somebody else is looking for the Doctor too and, as the Doctor is taken away to meet an old enemy, Missy and Clara find themselves on Skaro, the planet of the Daleks.
