Earth, the near future. When an archaological dig at the village of Devil's End goes disastrously wrong, an ancient power begins to revive. Can even the Doctor withstand the power of the Daemons? And just what is the local vicar up to in his spare time?

With the Doctor frozen by the energy release from the barrow, Jo calls Yates and Benton for help, but when the Brigadier tries to join them he finds the village surrounded by a heat barrier.

The Doctor explains to his friends that the Master is trying to gain the power of the last of the Daemons, a race who influenced Earth's development, while the Master brings the rest of the village under his control.

The Master orders Bert to set a trap for the Doctor at the village while a concussed Jo makes for the cavern.

The Master decides to sacrifice Jo to Azal and when the Doctor and his friends try to intervene they come under attack from Bok.