cave-wife preparing to murder Sandra with a crude obsidian blade. Ignorant of her true identity, the astronaut sets his gun to kill, takes aim—and is pole-axed by Koenig's stun-blast. Koenig and a rescue party barge in, collect Sandra and Carter, and quickly withdraw. Led by the shrieking cave-wife, the cavemen pursue. Consumed by blood-lust, they are easily decoyed to the mysterious ravine, where Koenig and Bergman have prepared an ambush. Knowing the answer must lie within the mist, they fire repeated near-misses at the cave-people to drive them into it. The cave-wife is the last to enter. As the vapour engulfs her, she peers at Koenig with recognition and utters her first intelligible word—John. Going round to the other side, Koenig watches as restored Alphans, led by Helena, emerge from the mist. Back on Alpha, all those affected are given a full medical work-up. The results show no after effects from their experience on Retha. Bergman speculates the ravine was the nexus of a time warp. The temporal field present in the mist caused the regression of their bodies (clothes and equipment included) to an earlier stage of evolutionary development; the transformation extended to their minds, giving them a Cro-Magnon level of knowledge and intelligence. Unfortunately, there will be no opportunity for a proper study as the Moon has since moved out of range of the planet. To the professor's annoyance, no one has retained any memory of being a Stone-Age person. He had hoped to learn how the human psyche has evolved after 40,000 years. Sandra's debriefing shows the inability to communicate fostered fear and anger. Helena admits the cave-wife expressed feelings of jealousy and vengeance for the same reasons she would. Bergman ruminates if man ever will change... Cast Starring Martin Landau — Commander John Koenig Barbara Bain — Doctor Helena Russell Also Starring Barry Morse — Professor Victor Bergman Featuring Prentis Hancock — Controller Paul Morrow Clifton Jones — David Kano Zienia Merton — Sandra Benes Anton Phillips — Doctor Bob Mathias Nick Tate — Captain Alan Carter Oliver Cotton — Spearman Uncredited Artists Suzanne Roquette — Tanya Colin Rix — Eagle One Co-Pilot Sarah Bullen — Kate Chai Lee — Nurse Alan Meacham — Dead Caveman (Sandos) Music An original score was composed for this episode by Barry Gray. The primitive, percussive compositions would be supplemented with his work from previous Space: 1999 episodes (especially "Another