Alethea Charlton

Matters get out of hand when the servants mock their employers while they are away.

With 1963 London left behind, the teachers are amazed to find themselves on prehistoric Earth and are taken captive by a tribe of cavemen who are searching for the secret of fire.

Kal has been banished from the tribe and Ian is making fire for Za in the hope that he will be grateful and will allow them to return to the TARDIS.

The time travellers manage to escape the tribe but their path to the TARDIS through the forest holds dangers of its own. Meanwhile, Kal attempts to take advantage of events.

The Doctor is held prisoner by the Monk in the monastery whilst Vicki and Steven search for him. Meanwhile, a Viking war party arrives ahead of the main invasion fleet.

Steven and Vicki discover an atomic bazooka. It seems that the Monk has plans for the Viking invaders. Returning to the Monastery, Steven and Vicki make an amazing discovery.