Earthsearch: A Ten-Part Adventure Serial in Time and Space is a British science fiction radio series written by James Follett. It consists of ten half-hour episodes. It was first broadcast on BBC Radio 4 between January and March 1981. There is also a novelisation by Follett of the same name. The series has been released on cassette and audio CD. Since 2003 it has been re-broadcast, several times in the Seventh Dimension science fiction slot on BBC 7 and its successor BBC Radio 4 Extra.

A sequel, Earthsearch 2 was broadcast between January and March 1982. There is also a novelisation by Follett under the title Earthsearch 2: Deathship. The series has been released on cassette and audio CD, and has been rerun several times on BBC Radio 4 Extra beginning in 2003.

Earthsearch

Main cast Commander Telson - Sean Arnold Sharna - Amanda Murray Darv - Haydn Wood Astra - Kathryn Hurlbutt Angel One - Sonia Fraser Angel Two - Gordon Reid

Other cast (across the series): Commander Sinclair - Christopher Scott Simon - David Bradshaw The Sentinel - Alexander John George - John MacAndrew Helan - Judy Franklin Emperor Thorden - John Bott Thail - Graham Faulkner Spegal - Stephen Garlick The Custodian - Eve Calfe Fagor - Sion Probert Krol - Michael Spice Dren - John Webb Lenart - Jane Knowles Tandor - Pauline Letts No. 41 - John Church

Episodes Planetfall First Footprint City Sands of Kyros The Solaric Empire The Pools of Time Across the Abyss New Blood Marooned Star Cluster: Tersus Nine Earthfall

Story

Three crew-generations previously, the starship Challenger - a vast ten-mile-long survey vessel – was launched from Earth on an interstellar mission to search the universe for an Earth-type planet to colonise. This has been unsuccessful, and the ship's once enormous crew-count has now been reduced to four. Telson (the ship's Commander), Sharna (Science officer), Darv and Astra are the third-generation crew- the only survivors of the disastrous Great Meteoroid Strike which seriously damaged the ship two decades previously, killing the entire second-generation crew and rendering large areas of the ship "uncontrolled" and inaccessible to its electronic systems.

From infancy, the four third-generation crew members (now in their early twenties) have been raised by robots and by the Angels – mysterious unseen beings who run the ship and who only manifest as disembodied voices. Darv, the most sceptical and enquiring of the crew members, suspects that the Angels are merely computers; but the others consider them as "Guardian Angels" and work entirely under their guidance.

With no suitably colonisable planet found after over a hundred years of searching, a crew-vote is taken and the Challenger sets a course for the return to Earth. Darv and Astra, while exploring one of the uncontrolled zones, find a survey recording of an Earth-type planet called Paradise. (In the accompanying novelisation, Darv is alone when he makes the discovery.) As is standard procedure, the crew enter suspended animation in order to prevent ageing and possible death during the many years of journey time.

Unrevealed to the crew, the Angels (who are the ship's control computers; their name being an acronym of ANcillary Guardian of Environment and Life ) have their own agenda. They desire absolute control and mastery over any colony resulting from the mission. To this end, they covertly engineered the apparent accident which killed the second-generation crew (who would otherwise have ended the mission before the Angels wanted it to end) and have kept the third-generation crew sexually immature and innocent via drugs and disinformation in order to keep them more tractable. However, their machinations have begun to backfire already. Their requirement of a minimum human crew of four to man the Challengers control room requires the Angels to work mainly via suggestion and manipulation. Also, the Great Meteoroid Strike damaged the ship and their control over it more than was planned, including damage to their own memory banks, which in turn deprived them of vital information about the Theory of Relativity. Concerned that the discovery of the Paradise recording may convince the crew members to change their plans, the Angels suppress Darv's and Astra's memories of the survey recording by hypnotic manipulation, in Darv's case by using violent, nightmare-inducing imagery.

Reaching the planetary system, the Challengers crew are horrified to discover that Earth has vanished altogether, with the Moon now occupying Earth's former orbit. Although the crew locate a large city on the Moon, they are unable to receive any answers to their communications and are unable to leave the ship to explore. This situation is changed when Darv and Astra enter an uncontrolled zone within the Challenger and locate a space shuttle previously unknown to the Angels. Using this, they visit the city, named "first Footprint City", and discover the Moon Sentinel, a computerised guardian and archive whom they can question. From the Sentinel they discover that while only one hundred and fifteen years of shipboard time has passed during the Challengers entire mission, due to the ship's use of near-lightspeed travel and the effects of time dilation much more time has passed on Earth – over one million years. During this time, the Earth was removed from the Solar System via a tremendous feat of interstellar engineering – desiring to protect the planet from the risk of increased solar activity, the inhabitants of Earth took the planet to orbit another, safer star. The Sentinel does not know which planetary system Earth now occupies, but notes that if the Challengers crew genuinely are descendants of Earth people they will think as the people of Earth thought, and will find the Earth by following that pattern.

Seeking more clues in their new Earthsearch mission, the Challenger travels to Kyros (the third planet of the Solar System, and a desert world). However, Darv's enquiring and rebellious mind is now putting him at odds with the Angels again, who are forced to surreptitiously discipline him for a second time. Opting to work in the ship's farm galleries for a while, Darv develops a taste for unprocessed fruit, and the hormone suppressants which keep him sexually undeveloped begin to wear off. He introduces Astra to the same diet, with similar effects. On arrival in Kyros orbit, Darv and Astra take the shuttle down to the planet surface to investigate a buried gravitational anomaly. While there, they are kidnapped, leaving the Challenger minus half its crew (and consequently stranded).

Darv and Astra's kidnappers turn out to be members of the Solaric Empire - an organisation based on the fifth moon of Zelda (the gas-giant fourth planet in the Solar System) and consisting of the remaining humans in the system. Darv and Astra's artificially-maintained sexual immaturity leads to them being labelled as poor-quality alien replicas of human beings. Their stories of the past of Earth and their mission are considered a threat to the position of the Solaric Emperor Thorden, who is persuaded by his ruthless chief prosecutor, Helan, to have them executed. This is thwarted by the arrival of the Challenger (Telson and Sharna having worked out how to use surgical androids as temporary control room crew replacements).

Following the subsequent standoff Thorden offers to join the Challenger on its search for Earth. He bluntly confirms to the crew that the Angels are computers, of the dangerous "freewill" kind that develop an obsession with power and which the Solaric Empire fought and won a war against (the defeated machines were imprisoned in a vault on Kyros, the anomaly investigated earlier by the Challenger crew). He plans for his own security and future dominance over the mission by ensuring that the space ferry which he brings to and docks within the Challenger as personal transport is heavily armed. He also smuggles on board a fearsome warrior android called Fagor.

Unknown to the crew, he strikes a deal with the Angels to share power over the Earth once it is found. However, the Angels have other plans. Once the humans on ship have entered suspended animation for the next leg of the journey, they cancel the crew's hormone suppressants and allow them to develop to full sexual maturity, suppressing any shock or curiosity via post-hypnotic suggestion (although Darv and Astra, who had previously begun to develop following their rejection of the processed food, had already begun a fully sexual relationship before this).

When they next revive the crew, the Angels allow the revival process to go wrong for Thorden, killing him as a result. Though Darv is suspicious of the Angels, he and the crew are more concerned with the drifting ship which the Challenger has picked up on its radar – which turns out to be the Challenger II, their own craft's sister ship, which appears derelict. Sharna and Telson go over in the shuttle to investigate, and discover that the Challenger II is still populated by the descendants of its original crew but has been crippled by civil wars between them. The survivors are divided between the initially welcoming, highly religious Earth Worshippers who are in conflict with the more anarchic but historically-aware Underpeople - the Earth Worshippers decide to hang Sharna and Telson for unintentional blasphemy. (In the novelisation, they also destroy the shuttle.)

Meanwhile, the warrior android Fagor begins to wreak havoc onboard Challenger in revenge for Thorden's death: Darv and Astra are forced to flee from him in Thorden's ferry. Aided by Lenart, a female Underperson, they rescue Telson and Sharna from the Earth Worshippers, but their subsequent visit to the Underpeople puts them into further peril. While welcoming, the female-dominated Underpeople have chosen to stabilise their society by keeping their men almost permanently in suspended animation, reviving them only temporarily to serve as sperm sources for impregnation. Darv and Telson have been targeted to bolster the Underpeople's dwindling genetic stock.

Successfully fleeing Challenger II in the shuttle and Thorden's ferry (in the novelisation, just the ferry), the Challenger crew discovers that Challenger itself has disappeared. Fagor has seized control of the ship and is accelerating it away with the intention of plunging it into a star to avenge Thorden. Abandoning the too slow shuttle, the crew carries out a harrowing pursuit in the ferry, constantly trying to produce enough velocity to cut down on a fatal time and oxygen shortfall. The Angels manage to trick Fagor into leaving the Challenger and flying via his own onboard jets to attack the ferry, hoping that the humans will destroy him with the ferry's armament. This is successful, with Darv discovering that firing the cannon can also produce sufficient thrust to reach the Challenger in time. The crew re-enter suspended animation for the next part of the journey, but during their medical examinations the Angels discover that Astra is pregnant.

Wishing to maintain control of a future crew – and already wary of the rebellious Darv – the Angels plan to deliver Astra's baby secretly. With these plans thwarted when they're obliged to bring Astra out of suspended animation to avoid a miscarriage, they're also forced to awake everyone in order to avoid arousing her suspicions. This is a particular risk for them as the ship is by then passing close to the Paradise planetary system as detailed in the records found earlier by Darv. The Angels fear that the crew may still opt to colonise an undeveloped planet rather than lead the Angels to dominion over a developed one.