The Return of the Forgotten Broadcast September 2nd 1967
Mission date 1541.2 the Endeavour is surveying the Dyson system when it discovers an artificial satellite of the largest gas giant of the system. Closer investigation actually shows that it is a huge space ship. Spock at the science station speculates that it is a generational spaceship as there is no evidence of a jump drive. Then McKenzie picks up a weak signal emanating from the ship. “Emergency...emergency...this is the commander of the spaceship Deecha . A major catastrophe has occurred...’”Having detected an alien distress signal, the bridge crew listen to the sombre appeal. The voice of the alien commander tells how large areas of his ship are devastated, with thousands dead and hundreds sick and dying. The signal ends with a plea for immediate aid—then is revealed to be an automated transmission when it loops back to the beginning. While Scotty marvels that each deck measures one hundred square miles, and at the engineering skills required, the instruments register life signs.
Decker opts to mount a humanitarian mission, selecting personnel to assess the medical, scientific and material needs of the aliens. A team comprising of Reynolds, Summers, Spock,M’Beke, Stein and Blamire is beamed on board. Communications are inhibited by weak levels of atomic radiation saturating the ship's structure. The life signs are confirmed however, no one is there to greet them. They enter a dilapidated reception area accessed by two opposing corridors. Hoping to encounter the ship's inhabitants, Reynolds sets off with Stein down one corridor, sending Spock and Blamire into the other.
M’Beke and Summers remain behind. An examination of the area reveals a hatch blocked by rubble; when opened, it reveals a another corridor. Their investigation is interrupted when two tattered people emerge from the hidden passage. Male and female, they panicked. The man hides behind the rubble while the female attempts to communicate using frantic gestures. The nature of their fear becomes apparent when a brutish man springs from around the corner and viciously clubs Summers unconscious.
Reynolds and Stein have hiked miles down their corridor without seeing a soul. They are suddenly blinded by lights, held by two people fully encased in silver radiation suits. As they lower their weapons, the others raise their own and stun them. During this, Spock and Blamire encounter increasing damage as they proceed. Eventually, the corridor is completely obstructed, forcing them to turn back. Returning to the airlock, they find the area deserted...until discovering the terrified man hiding behind the rubble.
Finding the open hatch of the third corridor, Spock convinces the man to show them where the others went. Up ahead, a tribe of savages drag M’Beke, Summers and the woman to their camp, a settlement on the edge of a vast, overgrown arboretum. These inhabitants resemble futuristic cave-people—filthy, with unkempt hair and rotten teeth, wearing garments of homespun mixed with synthetic fabrics and adorned with accessories fashioned from technological items. There are no elderly or infirm members in the group.
In another area of the ship, Reynolds awakens in a tastefully appointed rest chamber to find himself under the scrutiny of a woman ( guest star Kate O’Mara). She apologises for the assault, but they were intruding. Introducing herself as Kharrean, the vessel's Director of Reconstruction, she tells him the plight of her people. The distress signal was triggered 1000 years ago, when all but one of their nuclear reactors exploded. Most of the vessel was heavily damaged. Thousands survived the explosions, but fell victim to the radiation. Out of 50,000 crew, only the fourteen in the command area were shielded from the catastrophe. As Reynolds boggles over the magnitude of the disaster, Kharrean states this chance encounter could be vital to their survival.
In the settlement, the prisoners are brought before a shrine, dominated by a wall-painting of a male god. The tribe, who call themselves ‘The Survivors’, gathers in a circle and the woman is pushed into the centre. There, the high priest benevolently examines her—then proclaims, “stranger” The pitiful wretch is dragged to a cubicle recessed in the wall and sealed in by a transparent door. A switch is ritualistically thrown and the chamber floods with blinding light; to M’Beke’s horror, the woman's body evaporates. Summers is selected next and, during the examination, is declared “stranger”. He, too, is sent towards his death. Guided to the Survivors' settlement by the man, Spock and Blamire arrive in time to witness this . They attack the settlement stunning the tribesmen and drag M’Beke and Summers back down the corridor.
In the command area, Kharrean presents Reynolds and Stein to Theaput (special guest star Patrick Wymark), the ship's AI. (Unknown to them, the image is the spitting image of the painting depicting the Survivors' god.). On seeing this image Stein looks very thoughtful. Reynolds notices this and asks why. Stein replies that he is not sure and would need to confirm something with the Endeavour. Stein soon makes an unsettling discovery. The crew are human but a study of their food production system shows no inventory of raw materials on the ship—yet the recycling plants are stocked with a steady supply of all the essential elements. Stein concludes the only possible source of these elements could be living human bodies. Appalled, Reynolds confronts Kharrean with these findings.
Indignant, Kharrean justifies their actions in the name of survival. When their own resources were exhausted, they discovered that descendants of the original survivors existed in the radioactive 'wilderness'—savage, degenerate creatures wiped clean of all civilised behaviour. They managed to teach them the basics of survival, giving them a god who taught them to preserve only the fit. The weak and the sick were to be sacrificed—as fodder for the food recycling system. Kharrean informs him their motivation was not self-preservation, but a greater survival...Kharrean reveals her sacred cause: a gene bank containing genetic material preserved and protected before radiation damaged their people. When they reach a new world, it will be used to produce colonists. They confess the survivor tribes are dying out and, without them, all life on the ship will perish .
Then Spock and the others arrive and Kharrean and the rest of her command crew are swiftly overwhelmed. Spock takes one look at the image of Theaput and exclaims “The Abbott”. Stein then exclaims “Of course!” Reynolds looks bemused until Spock tells him of the adventure on Adams III. This ship must have been launched just before “The Abbott” had taken over Adams III, the Theaput was the same software system.
Reynolds manages to contact the Endeavour and Decker contacts the fleet to send rescue vessels to ferry the survivors to their intended destination the third planet of this system which is stil luninhabited.