Derek Newark

The Avengers put the zap on a lethal ray that is murdering scientists.

In a spoof of the 1967 British TV series The Prisoner, Tara finds herself trapped in a posh prison without bars or guards, which, on the surface, appears to be merely an elegant hotel in a quiet English town.

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.

The time travelers 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.

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

Simon is on the trail of counterfeit money.