Doctor Who (1963)

S1E2 The Cave of Skulls

The mysterious Doctor, worried that teachers Ian Chesterton and Barbara Wright might expose his hidden truths to 20th century Earth, transports them along with his granddaughter Susan to prehistoric times. In this ancient world, the group becomes embroiled in the brutal power struggles of a tribe of cavemen who have forgotten how to create fire, leading them into a fight for survival and the chance to restore a vital skill to the struggling community.