Following a restful visit to a pastoral world, the Tardis is redirected to Earth by the CIA. The CIA (Celestial Intervention Agency) wish them to investigate an abnormal energy field. On leaving the Tardis they hear a scream and find a ransacked cottage. Two constables take them to be Scotland Yard detectives and invite to join the investigation of several disappearances. An old woman, Madame Sylvia, puts the events down to a ‘demon’ which has been woken by an archaeological dig. While investigating the dig, the party and Lord Denbigh are trapped in one of the tombs (however they manage to escape.) While looking for information at King’s College Cambridge library, the Nomad and the Professor discover Baron Von Mueller working on a map of the dig. While the Professor and Vivian attend a séance, Mac and Nomad investigate the dig.
They materialise in a huge warehouse aboard a even huger spaceship travelling at over 99% the speed of light. The Professor and Vivian stay in the Tardis while Nomad and Mac explore. The pair are captured by robots while exploring and placed in a cell some distance from the Tardis with a native by the name of Tovas (the leader of a rebel group.) While making an escape attempt they hear fighting on the other side of the cell door. Some of Tovas’s friends have arrived to rescue him. Nomad and Mac make friends with the group. The ship is ruled by someone/something called ‘Supreme’ and a ruling elite of Ydarans (the Captain Lords.) The society is stagnating, with the arts becoming more important than the sciences (indeed some are already lost.) The Ydarans are asked to fetch the others from the Tardis (only the Professor actually comes.) The act of allowing the Ydaran rebel see inside the Tardis finally convinces the rebel cell that the time travellers are from another world. They are led to an outcast Captain Lord who shows them an observation room. There they see a planet destroyed before their eyes. They now realise how close the ship is to Mutter’s Galaxy. Nomad, Mac and the Professor enter the Citadel (with the ‘help’ of a Captain Lord) and enter the Audience Chamber in order to speak to Supreme (who they are now convinced is a computer.) They convince the computer that it must alter its ways. The ship is diverted to follow a path which will enable it to use galactic ‘rubbish’ (dust, etc) to power it while it re educates the Ydarans and finds a world for them to colonise. Once more they set of for the Armageddon conference and Nomad correctly sets the space/time coordinates. They arrive in a tree lined avenue, the chameleon circuit already disguising the Tardis as a tree!
Vivian decides to go on a shopping expedition, leaving the rest to attend the Armageddon conference. Nomad is mistaken for ‘Trask Tynska’ from the planet Batone and the three of them are registered for the convention. The real "Trask Tyriska" is a gambler, charismatic and likes to seduce pretty women! Nomad’s ‘abnormal’ behaviour is noticed. They are befriended by another party from the planet Detane. It consists of Markus Trelawnie Edorian, his wife Eleanor; his daughter Michele; her aide Michael Stanton and his secretary Susan Ellas.
Detane is well known as producing arms of all kinds and every diplomat is in fact an arms dealer. At one of the opening debates, Markus Trelawnie Edorian is killed by a shot apparently fired from the service balcony (the Professor finds a blaster rifle which has ‘just’ been fired.) Since there is no paperwork to support their arrival on planet the party are blamed. Mac leads security to the Tardis which is promptly closed off by a blaster proof barrier. The party must find the real murderer and start investigating the diplomatic party. While the Professor is staking out the Edorian apartment, Nomad is almost killed by a deadly nerve gas. Suspicion falls on the daughter since there is a blaster hidden in her room and she is found ‘missing’. When she returns, it is discovered that she is in fact a Kamelion robot. The party search the service ducts and find a room with psionic amplification equipment and a beacon for transmitting signals through the vortex (to current TL Gallifrey.) The daughter shoots and almost kills Nomad. In the subsequent gun fight she is wounded and collapses. One of the other delegates is found to be aiding her in a plot to explode a large bomb at the closing speech, but his/her identity is not discovered. The plot is exposed and the party are allowed to leave.
The party leave for the planet Azure. They arrive, but on a space station orbiting the planet. There are signs that the station is deserted and they decide to explore it. After several encounters with blood-thirsty animals and men they discover that the station’s atmosphere has been ‘seeded’ with some form of combat drug. One of the remaining crew start the engines and the station starts to lose orbital speed. After restraining the remaining crew they inform the planet of the situation and leave. Vivian decides not to investigate and stays on Azure when they leave the planet. After a restful holiday, they set off for somewhere with a little more excitement, and discover a time corridor in the vortex. They follow the time corridor to its destination and find a Sontaran bridgehead on the planet Ultar.
The natives of the planet Ultar must evacuate their world before a nova destroys it. The Sontarans have opened up a bridgehead to raid the world for resources and equipment. After exploring their immediate area the party decide to micro-jump to a nearby city. There they are ‘found’ by military patrol. They manage to persuade the authorities that they can help the natives and start to involve themselves in the war. Mac scouts the perimeter of the Sontaran base. After several close shaves with recon drones, he finds a hidden entrance into the base. Nomad works on a device to disable the recon drones. His own efforts produce no device, but he inspires one of the technicians to produce an ‘electronic’ rifle. The Professor assists by suggesting alternative weapons to use in the fight. The authorities decide that the ‘electronic’ rifle requires a field trial. The party and an army technician approach the Sontaran base to see the weapon’s effect on the recon drones. The weapon proves successful but they axe almost trapped by a Sontaran force. It is decided that Mac should lead a commando force into the base while Nomad and the Professor disable the spaceship that the Sontarans have already stolen. The commando raid is successful and the base is destroyed along with the time corridor equipment. After several close encounters, Nomad and the Professor find a SIDRAT on the ship and destroy it. Unfortunately, Nomad suffers fatal wounds in the combat and regenerates. The Professor manages to disable the bulk of the Sontaran equipment and after a celebration feast they set the space/time co ordinates for Hunter’s world. While in the vortex the Tardis receives an ‘SOS.’ Nomad decides to follow the Signal and appears on Solaris to be greeted by a ‘Stephen Strange,’ -a sorcerer!
Nomad, having diverted the Tardis to the source of the signal, finds a primitive planet. They are met by Dr. Stephen Strange, a sorcerer from a distant world, who has harnessed the powers of psionics Strange was drawn to this world by Modred the Mystic, a criminal from his own world. Modred has set up an interference barrier around the planet, preventing Strange and the Tardis from leaving. Strange tells them of Modred’s tower, where the psionic amplifier is situated. Due to Modred’s new found power however, Strange himself cannot enter the tower hence his SOS to his home world for assistance (and intercepted by the Tardis.) They encounter Viva on the way to the tower. She is investigating the disappearance a number of her tribe. She leads them to a cave, which has a chair connected to an iron rod leading into the cavern roof. Her people were placed in the chair and their psychic energy was absorbed by the crystal above, via the rod (it extends right up to the tower above.) A stairway leads up, unknown to the party circling the iron rod. The way to the tower is protected by a series of traps based on the elements: the heat of fire, humidity of water, winds of the air, the earth and electricity. At the top of the tower, connected to the iron rod, is a large blue crystal, which is boosting Modred’s power. K 9, Nomad and the Professor fire on it, reducing it to shattered fragments (Nomad selects a shard as a souvenir of the trip.) They return to Strange’s cave to discover that, with the crystal destroyed, he fought and defeated Modred in a magical battle of wills. They stay on a few, days as a guest of Strange during which time Nomad picks up the art of sorcery (a Psionic Science.) from Strange. When rested, Strange returns to his own world and the Tardis sets off for Hunter’s World.
The Tardis is caught by an energy net in the vortex and dematerialises in a metal walled room with half columns against the walls. It was originally meant to catch the Master’s Tardis, but caught them as well. Special circuitry will fry both Tardises if they try to escape. They are invited out of the Tardis by an automated voice which threatens to destroy the Tardis if they don’t leave it (it mentions the Master by name.) Unknown to them, the Master is watching from his own Tardis (disguised as a column.) They are trapped in a zoo built with Gallifreyan technology. It consists of a number of large arenas (each large enough to look like a small valley) and each of which simulate an environment type. Hidden projectors project a sky/sun image. There is a gallery around each for spectators to view the scenery. All the wildlife in the zoo is natural and there are many vicious predators. Visitors normally wander around in special force suits, to protect them against the flora and fauna. Each of the robots within the complex has been programmed to attack and kill any humanoids they see (the Master and party.) Trapped with the Master, they must help him and themselves escape by finding the control mechanism and destroying it. The complex has had a number of fatal traps built into it: energy-draining devices (to kill K 9) vicious traps in the paths to disable/kill people (cf. Vietnam), lift monitors include Stasters and communication devices have been fitted with hypnotic devices. The facilities have been fitted with deadly traps to go off when used. The party and Master go straight to the mechanism, only to find the rooms leading to it are also guarded by a series of traps (examples follow):
They bypass the traps and destroy the mechanism. The Master then summons his Tardis and manages to escape before the party can stop him.
While in flight, the cloister bell appears to sound (only the echo is heard.) The Companions find the only memories they have are of the Tardis and its adventures. They are informed by Gallifrey that the human race has disappeared from the timestream and that they are to investigate (they are given a set of co ordinates.) When they materialise, the sensors show a second Tardis is in operation in close proximity. They prepare for an expedition and set of through the jungle to investigate. On the way they encounter a dinosaur, which they drive off. K 9 informs them that there is a temporal barrier, that only it’s creators can cross, surrounding the second Tardis.
Mac, in his explorations, walks through this barrier without any difficulty as Nomad investigates it! Inside the barrier are the ruins of an Aztec city, in the centre of which is a step pyramid. On top of the pyramid is an antenna-like grid, and in the middle of this a Tardis, with its door open. A cable leads from the Tardis to some machinery and to the metal grid. A second, power cable, leads into the pyramid. Connected to the mechanism is a coffin sized box with a human figure inside. All the controls and surfaces are protected by a force shield. The Tardis is an identical twin to the one they arrived in! They retire to consider the consequences, and discover a time loop is in operation. They set of to track down the cause of the problem. They materialise in the past, close to the Aztec city they have just left. They are making their way there when they are captured by conquistadors, searching for El Dorado They are led back to the Spanish camp but escape under the cover of darkness. They find the Tardis missing, dragged off to the Aztec city. While heading to the city, they are ambushed by a group of Silurians and natives. During a fight between the Spanish tailing the group and the ambushers Viva is captured but the rest manage to escape, aided by an Aztec prince. The prince leads them to safety.
The Silurians plan to use the Tardis (opened by Nomad’s dropped key) to start up a genetic time loop so that they are rid of these mammalian vermin forever. Viva is locked up in a stone cell within the pyramid. While Nomad contacts the Spanish (to act as a distraction by attacking the city), the rest plan to sneak into the city to free Viva. The Spanish attack the city and Nomad makes his way to the pyramid, as do the rest of the group (avoiding the Silurians.) Meanwhile Viva has escaped unaided. They all meet up outside the pyramid and the Professor uses his Staser skill to stop pursuers. K 9 informs the Timelords that there are Silurians in the Tardis! Viva rushes into the Tardis and is badly injured Nomad surrenders to prevent her death. Nomad informs the Professor of reinforcements (in Gallifreyan), but he is overwhelmed and suffers severe damage causing a regeneration (he uses up two regenerations in doing so.) Mac reminds Nomad about the effects of ultrasound on Silurians and along with K 9 they retire to the Secondary Control Room. Nomad lowers the rest mass of the Tardis, sends an ultrasonic sound through the Tardis (driving out the Silurians.) he then breaks the connections between the Tardis and the machinery and finally micro-jumps away from the area. While making repairs, the Silurians attack the Tardis and Nomad decides to leave. With the successful shutdown of the time loop, the city, the Silurians and the conquistadors disappear from TNP Earth’s history, leaving only the legend of the El Dorado: The City of Gold.