Colony ship (World Enough and Time)

A Mondasian colony ship travelled from Mondas to pick up some colonists. When the ship almost traversed into a black hole, the crew experienced the effects of time dilation, causing time on the higher levels of the ship to slow down in comparison to the lower floors, to the point that a thousand years passed on Floor 1056, the lowest floor, in the space of less than two and a half days on the flight deck.

When a team of engineers found themselves trapped on the bottom floor, they were forced to spend the rest of their lives down there; a thousand years after settling on Floor 1056, a huge city had formed and eventually degenerated significantly after centuries of occupation by the ship's engines. To survive, the residents evolved into Mondasian Cybermen, (TV: World Enough and Time) and after – who had crashed his TARDIS on Floor 1056 more than ten years prior – lost control of them, the Cybermen spent centuries evolving themselves into more advanced forms, determined to convert the entire ship and complete the final stage of their original mission: Operation Exodus. (TV: The Doctor Falls)

Layout
The ship was approximately 400 miles long and around 100 miles wide.

Decks
The ship contained over a thousand decks, with various different purposes and landscapes. These included:
 * 0000 - The ship's flight deck. (TV: World Enough and Time)
 * 0502 - A deck containing a solar farm. (TV: The Doctor Falls)
 * 0507 - A deck containing the largest of the ship's solar farms. (TV: World Enough and Time) The locals here were saved from the Cybermen by the Twelfth Doctor, Bill and Nardole, although the floor was reduced to an incinerated wasteland as a result. (TV: The Doctor Falls)
 * 0508 - An agricultural deck, designed to automatically produce food for the floor's population, as well as those of the nearby floors, such as Floor 0507. Sometime after being abandoned,, and Alit prevented a Cybermat attack from some CyberNeomorphs. (PROSE: Alit in Underland)
 * 0900 - A city deck. The Cybermen flew through this floor on their way to Floor 0507. (TV: The Doctor Falls)
 * 1056 - An urban deck, containing various apartment blocks and a hospital. (TV: World Enough and Time) Eventually turned into a Cyber-factory. (TV: The Doctor Falls)
 * Other floors mentioned on the lift scanner are: 1052, 1051, 1050, 1049, 1048, 1047, 1046, 1045, 1044, 1043, 1042, 1041, 1040, 1039, 1038, 1037, 1036, 1035, 1034, 1033, 1032, 1031, 1030, 1029, 1028, 1027, 1026, 1025, 1024, 1023, 1022, 1021, 1020, 1019, 1018, 1017, 1016, 1015, 0951, 0950, 0949, 0948, 0947, 0946, 0945, 0944, 0943, 0942, 0941, 0940, 0939, 0938, 0937, 0936, 0935, 0934, 0933, 0932, 0931, 0930, 0929, 0928, 0927, 0926, 0925, 0924, 0923, 0922, 0921, 0920, 0919, 0918, 0917, 0916, 0915, 0914, 0913, 0912, 0911, 0910, 0909, 0908, 0907, 0906, 0905, 0904, 0903, 0902, 0901, 0899, 0898, 0897, 0896, 0895, 0894, 0893, 0892, 0891, 0890, 0889, 0888, 0887, 0886, 0885, 0884, 0737, 0736, 0735, 0734, 0733, 0732, 0731, 0730, 0729, 0728, 0727, 0726, 0725, 0724, 0723, 0722, 0721, 0720, 0719, 0718, 0717, 0716, 0715, 0714, 0713, 0712, 1711, 0710, 0709, 0708, 0707, 0706, 0705, 0704, 0703, 0702, 0701, 0700, 0699, 0698, 0697, 0696, 0695, 0694, 0693, 0692, 0691, 0690, 0689, 0688, 0687, 0686, 0685, 0684, 0683, 0682, 0681, 0680, 0679, 0668, 0667, 0666, 0665, 0664, 0663, 0662, 0661, 0660, 0659, 0658, 0657, 0656, 0655, 0654, 0653, 0652, 0651, 0650, 0649, 0648, 0647, 0646, 0645, 0644, 0643, 0493, 0492, 0491, 0490, 0489, 0488, 0487, 0486, 0485, 0484, 0483, 0482, 0481, 0480, 0479, 0478, 0477, 0476, 0475, 0474, 0473, 0472, 0031, 0030, 0029, 0028, 0027, 0010, 0009, 0008 and 0007. (TV: World Enough and Time)
 * Other floors mentioned on the lift level indicator at Floor 0000 are: 0995, 0994, 0993, 0992, 0991, 0990, 0989, 0988, 0987, 0986, 0985, 0984, 0983, 0982, 0981, 0980, 0979, 0978, 0977, 0976, 0975, 0974, 0973, 0972, 0971, 0970, 0969, 0968, 0967, 0966, 0965, 0964, 0963, 0962, 0961, 0960, 0959, 0958, 0957, 0956, 0955, 0954, 0953, 0952, 0363, 0362, 0361, 0360, 0359, 0358, 0357, 0356, 0355, 0354, 0353, 0352, 0351, 0350, 0349, 0348, 0347, 0048, 0047, 0046, 0045, 0044, 0043, 0027, 0026, 0025, 0024, 0006, 0002 and 0001. (TV: World Enough and Time)
 * Further floors mentioned on the lift level indicator at floor 0507 are: 0797, 0796, 0795, 0794, 0793, 0793, 0792, 0791, 0790, 0789, 0788, 0787, 0786, 0785, 0784, 0783, 0782, 0781, 0780, 0779, 0778, 0777, 0776, 0775, 0774, 0773, 0772, 0771, 0770, 0769, 0768, 0767, 0766, 0765, 0764, 0763, 0762, 0761, 0760, 0759, 0758, 0757, 0756, 0755, 0754, 0753, 0752, 0751, 0750, 0749, 0748, 0747, 0746, 0745, 0744, 0743, 0742, 0741, 0740, 0739, 0738, and 0509. (TV: The Doctor Falls)
 * Although she did not specify any floor numbers, Alit stated that there were laboratory levels. (PROSE: Alit in Underland)

Each level would move a little slower than the one below it, due to the time differential, from proximity to the black hole. (TV: World Enough and Time, The Doctor Falls)

Crew
At take off, there were fifty crew members aboard the ship. They included at least twenty engineers, the chief engineer Franq, the Captain, (PROSE: Jorj) and Jorj, the janitor, (TV: World Enough and Time) and the man responsible for checking for stowaways prior to the ship's launch from Mondas. (PROSE: Jorj) Following the effects of the time dilation from the black hole, the bottom floor became filled with generations of lifeforms, each descended from the ship's crew, in a huge city. The hospital on this floor became the genesis point for a race of Cybermen. (TV: World Enough and Time) A colony of farmers and children lived on Floor 0507, although following the Cybermen's attack, they were evacuated by Nardole and Hazran to Floor 0502. (TV: The Doctor Falls) A team of farmers were also based on Floor 0508, although their whereabouts following the rise of the Cybermen on Floor 1056 was unknown. (PROSE: Alit in Underland)

Technology
The ship was fitted with super-fast inertia lifts and was propelled by rear thrusters. Aboard the lowest decks, evolution of technology was advanced. In order to adapt to expiring environments, an artificial evolution was devised. The Mondasian inhabitants were gradually upgraded into Cybermen. (TV: World Enough and Time)

The black hole
At an unknown time after the human Mondasians had evolved on Mondas, the colony ship was launched from Mondas to pick up some colonists, with a skeleton crew of fifty, including the Captain, chief engineer Franq and Jorj, the janitor and only non-human. On day 43 of its voyage, it was drawn into the gravity well of a black hole. After the Captain berated Jorj for not alerting him of the black hole sooner, a team of twenty engineers, including Franq, were sent from Floor 0000, the flight deck, to Floor 1056, the lowest level, to reverse the rear thrusters and escape the black hole. However, time dilation caused by the black hole's gravity resulted in time passing much more slowly on the higher floors of the ship in comparison to the lower floors, as the higher floors were closer to the black hole. (TV: World Enough and Time, PROSE: Jorj)

The deterioration of Floor 1056
As a result, the team at the bottom of the ship found that, after reversing the rear thrusters, they were unable to return to Floor 0000. Forced to spend the rest of their lives on Floor 1056, they established a huge civilisation that their descendants inherited over several centuries, but over time, the city deteriorated significantly as the bottom of the ship aged dramatically, whereas the higher floors, in particular Floor 0000, aged far more slowly. (TV: World Enough and Time)

At some point,, after being cured of his "little condition" and banished from Gallifrey, (TV: The End of Time) arrived on Floor 1056; he attempted to escape the black hole but flew his TARDIS too fast, burning out the dematerialisation circuit and stranding him on the colony ship. The Master then "killed a lot of people, took over the city [and] lived like a king" before the people of Floor 1056 got tired of his cruelty and overthrew him. The Master was forced into hiding as "Mr. Razor", (TV: The Doctor Falls) the caretaker of the city's hospital.

Operation Exodus
By this time, conditions on Floor 1056 had rendered the floor inhospitable to human life, to the point that the hospital began Operation Exodus, an operation with the intent of transforming the people of the city into cyborgs to dramatically extend their life spans, so that they could not only survive on Floor 1056, but also survive the journey to Floor 0000 to take command of the ship. (TV: World Enough and Time) However, following the manipulations of Razor, the cyborgs that were produced from Operation Exodus were a race of Cybermen (TV: The Doctor Falls) that the Master intended to use to conquer the galaxy. (PROSE: Alit in Underland)

The "patients", an early form of Mondasian Cybermen, were used to escort people from the city to be converted in the hospital, and were also sent to the higher decks to capture any other humans for conversion. (TV: World Enough and Time) One team of patients were sent to Floor 0507, but were attacked by the farmers living on the floor, who shot them down at night and chained them to crucifixes in the fields during the day. However, at night, the patients sometimes broke free and resumed their original mission, forcing the farmers to constantly fight them off. (TV: The Doctor Falls) On Floor 0000, the day after Franq and the original twenty engineers were sent to Floor 1056, Jorj detected hundreds of life readings at the bottom of the ship. The Captain sent another team to Floor 1056 to deal with the "stowaways”, but when the lifts returned, a patrol of patients arrived, who captured the remaining humans and took them back to Floor 1056, leaving Jorj behind due to him being non-human.

By the next day, (PROSE: Jorj) Jorj had broadcast a distress signal; in response, the Twelfth Doctor,, Bill Potts and Nardole arrived. Jorj threatened to shoot them, after Bill's human life-signs were detected by the hospital on Floor 1056, who, in response, sent a team of patients in the lifts to capture her. When the lifts arrived, Jorj shot Bill despite the Doctor's efforts to stop him, and the patients took her back to Floor 1056 where she was revived and fitted with a chest unit in the floor's hospital. Waking up months later, she met "Razor", and spent ten years waiting for the Doctor on the bottom floor, until Razor eventually tricked her into entering the Conversion Theatre, where she was fully converted into a Cyberman.

Meanwhile, the Doctor, Missy and Nardole explained the time dilation and its effects on the ship to Jorj, before knocking him out and making their way down to Floor 1056. (TV: World Enough and Time) During their descent, a portal opened inside the group's lift, and a hand emerged asking for them to "grab on", before quickly disappearing. (COMIC: The Road To...) Once on the bottom floor, the Doctor and Nardole left Missy to investigate a computer terminal whilst the duo found a backdoor to the Conversion Theatre, as well as the converted Bill. During this, Razor revealed his true identity to Missy, (TV: World Enough and Time) and the two Masters knocked out the Doctor in a fight, during which the Doctor quickly used a computer to alter the Cybermen's definition of humanity. The Master and Missy then took the unconscious Doctor to the hospital roof, followed by Bill.

With Floor 1056 transformed into the Cyber Foundries, the Doctor woke up before the Cybermen began attacking the hospital due to the Doctor's tampering causing the Cybermen to register him and the two Masters as humans. Following Nardole's arrival in a shuttlecraft from the floor's loading bay, the Master, Missy, Bill and an injured Doctor escaped and eventually crashed on Floor 0507.

Meanwhile, the Cybermen, now no longer controlled by the Master, began preparations for the final assault on the colony ship, and the eventual completion of Operation Exodus. As they began to upgrade themselves over the span of hundreds of years into radically more powerful forms – in an example of parallel evolution (TV: The Doctor Falls) - they eventually installed a Cyber-Planner on Floor 1056 to serve as their strategist and overall leader, as well as a number of Cybermats, and at least seven Mondasian Cybermen were evolved into CyberNeomorphs, including a Cyber-Leader and Cyber-Lieutenant. (PROSE: Alit in Underland)

Floor 0508
Following the shuttlecraft's crash-landing on Floor 0507, the Doctor, Bill, Nardole, the Master and Missy arrived at a large farmhouse, where the Doctor received treatment for his injuries. (TV: The Doctor Falls) The Master and Missy tried to get to Floor 0508 to regain control of the Cyber-army but were found by Alit. Whilst exploring the walkways for an entry point to Floor 0508, the trio were pursued, and attacked, by a patient whom Alit had fled from on Floor 0507; Missy parried it long enough for the Master to reprogram it to respond to his voice commands, turning the patient – who Missy had begun referring to as "Topknot" – into the Master's slave. The group then descended into Floor 0508 via a service lift.

The Master, Missy, Alit and Topknot spent the next day riding on various forms of automated farming machines through the fields, eventually arriving at a large collection of storage silos for farming produce, where they encountered a group of six CyberNeomorphs, led by a Cyber-Leader and a Cyber-Lieutenant, who had been tasked with capturing the Master and Missy for interrogation, as well as deploying the Cybermats to attack Floor 0507. Escaping with Alit, Missy managed to confuse the Cybermen's life-sign scanners long enough for her to hack into the ship's systems in a weather control tower, and reactivated an old failsafe system in the Cybermats, trapping them back on Floor 1056. Using Topknot as bait for the Cybermen, Missy and Alit rescued the Master, who had been knocked out by the Cyber-Leader, before destroying the Cybermen with an electrical burst generated by the Master's laser screwdriver, the forced rain, and the steel deck of Floor 0508. The trio then returned to Floor 0507, taking a horse from a stable and riding back to the solar farm. (PROSE: Alit in Underland)

The battle of Floor 0507
Back on Floor 1056, the Cybermen continued to spend centuries evolving themselves, with a number of troops evolving (TV: The Doctor Falls) into models reminiscent of the Cybermen of the Cyber Legions (TV: A Good Man Goes to War) and the Cyberiad. (TV: Nightmare in Silver)

Meanwhile on Floor 0507, two weeks after the the Doctor, Bill, Nardole, Missy and the Master had arrived, the residents of the solar farm had prepared defences around the farmhouse for an inevitable attack from the Cybermen. During this time, the Master and Missy found the floor's lifts, showing them to the Doctor and Bill. However, when Missy called one of the lifts, the four were forced to destroy a Cyberiad-type Cyberman when it emerged from the lift. Noting that the Cybermen now knew where they were, Missy argued that everyone could travel to Floor 0000 and escape in the Doctor's TARDIS, but the Doctor explained that doing so was too dangerous as the time dilation meant the Cybermen would have thousands of years to formulate a plan to stop them all escaping.

By the time the Doctor, Bill, Missy and the Master returned to the farmhouse with the dead Cyberman, the Cybermen – having spent an unknown amount of time upgrading even further so as to achieve flight capabilities – sounded an alarm to the humans of Floor 0507 before initiating their attack phase, with hundreds of Cybermen of all three variants taking off from Floor 1056, blasting through hundreds of floors (such as Floor 0900) to reach Floor 0507.

As final preparations began on Floor 0507, the Doctor and Bill found a sealed service duct connecting to the farmhouse's cellar, which Bill promptly burned open with her Cyber-gun. Outside, Nardole used a laptop to hack into the fuel systems underneath the solar farm, and after some tests, created the impression that the rifles could fire highly explosive rounds, when in truth Nardole was simply causing powerful controlled explosions by igniting the fuel lines that corresponded to where the rifles were being fired to. The Doctor explained that they could use this to trick the Cybermen into believing that the humans were far more dangerous than they initially seemed.

That night, the Cybermen arrived and battle commenced, with the Cybermen initially taking heavy losses as Nardole erupted several fuel lines, destroying them. When the Cybermen withdrew, Hazran began rounding up all the children in the cellar, and she and Nardole led the evacuation to Floor 0502, where there was another solar farm. The Doctor downloaded all of Nardole's hacking software into his sonic screwdriver and stayed behind with Bill to hold off the Cybermen long enough so that the humans could evacuate.

Meanwhile, the Master and Missy tried to escape to the Master's TARDIS on Floor 1056 using the lifts in the forest, but Missy, having changed her mind about not helping the Doctor, stabbed her previous self in the back, giving him just enough time to get back to his TARDIS on Floor 1506. However, he killed her in turn, leaving her laying in the forest, seemingly dying. (TV: The Doctor Falls) Before she could die, Missy used an Elysian field to "kick start a new regeneration cycle", regenerating into the Lumiat, before also leaving the colony ship. (AUDIO: The Lumiat) When the Cybermen prepared to attack the farmhouse again, Bill and the Doctor headed into the forest in opposite directions to fight them. The Doctor was eventually shot, but managed to ignite all the remaining fuel underneath Floor 0507 before he could regenerate or be shot again, destroying the remaining Cybermen in a gigantic explosion. (TV: The Doctor Falls)

Aftermath
Following the destruction of the Cybermen on Floor 0507, the Doctor, severely wounded, observed the last few explosions before seemingly dying. Sometime afterwards, the Cyber-converted Bill, scorched and barely functioning, found the Doctor's body in what remained of the forest, the whole of Floor 0507 having been reduced to nothing more than an uninhabitable wasteland. As she began to cry, however, Heather materialised from a rain puddle, having reached Bill (TV: The Doctor Falls) due to the former leaving Bill with her tears. (TV: The Pilot) Heather transformed Bill into a creature of sentient oil like herself, causing Bill's Cyber-form to collapse to the ground, the final casualty of the battle. The two then returned the Doctor's body to his TARDIS on Floor 0000. Heather then placed the TARDIS in flight, leaving the colony ship.

After the evacuation of the residents of Floor 0507 to Floor 0502, Nardole waited outside one of the lifts. Alit suggested that the Doctor and Bill might arrive, but Nardole dismissed the thought. He then explained to Alit that the few remaining Cybermen on the ship would likely take some time to calculate a new plan before they attacked the humans again, and although he didn't initially have a plan, he assured Alit that he would have one soon. (TV: The Doctor Falls) Nardole and the humans continued to fight the Cybermen on a near–daily basis, during which he began contacting Bill via space-time telegraph. At one point he also fell nearly thirty feet in a banana meadow, breaking his leg and having to rely on the children to push him around in a wheelbarrow. (WC: The Best of Days)

Eventually, Nardole and the humans were able to end their conflict with the Cybermen and reduce their attacks to annual Cybermat incursions every spring. Nardole spent the rest of his life onboard the colony ship before dying at the age of 728, during which he had six wives, two of whom he was married to at the same time. At some point, the Testimony Foundation arrived at the colony ship and saved the memories of Nardole and his six wives immediately before their deaths so that they could live on as glass avatars. (PROSE: Twice Upon a Time)

On Floor 0000, sometime after the Doctor, Bill and Heather had left in the Doctor's TARDIS, Jorj woke up with a sore head from when the Doctor had knocked him unconscious before he left with Nardole and Missy for Floor 1056. As Jorj completed one of his many ship logs, an alarm sounded, which alerted him to the massive explosion caused by the Doctor on Floor 0507. Observing a number of life-signs moving up the colony ship, Jorj simply hoped that his status as a non-human would keep him safe from anyone, or anything, left on the ship. (PROSE: Jorj)

Nave colonial (World Enough and Time)