Floor 0508

Floor 0508, (TV: The Doctor Falls) also known simply as Floor 508, was a floor onboard a Mondasian colony ship. Located directly beneath Floor 0507, it served as a farming deck for growing and harvesting crops to feed the Mondasians living on it, as well as those living on the higher floors. (PROSE: Alit in Underland)

Landscape and technology
Floor 0508 was similar in appearance to Floor 0507, resembling a large countryside resembling those of 21st century Earth, with a holographic sky featuring the floor's number. Unlike Floor 0507, however, Floor 0508 was not a solar farm, but instead served as a large-scale producer of food and grain for the Mondasian carters living on the floor, as well as the farmers and children living on Floor 0507. However, following the evolution of the Mondasians of Floor 1056 into Cybermen, the whereabouts of these carters was unknown.

The farming technology of Floor 0508 was highly advanced and efficient, most of which moved around the fields of the floor on a large rail network, and were capable of functioning entirely autonomously. One machine, which lacked any sort of space for people to occupy, featured several control panels, and was as large as the farmhouse on Floor 0507. Another machine had two main sections - a small front, and a much larger back - with a long mechanical appendage extending out of the back; this machine was designed to plant crops and disperse a form of growth accelerator, and, like some of the other machines, was more suited to transporting people, although it was not designed for this purpose.

A network of storage warehouses was also present on Floor 0508, containing more simplified farming equipment, such as shovels, tools and gumshoes. A nearby control tower served as the hub for controlling Floor 0508's weather settings, containing a lift for transport to the tower's individual levels. (PROSE: Alit in Underland)

History
According to Alit, some carters, who lived on Floor 0508, transported the crops grown on Floor 0508 to Floor 0507 to feed the solar farm's population. However, following the rise of the Cybermen on Floor 1056, they didn't travel as much, and whether the Cybermen encountered them was unknown.

The night after their arrival on Floor 0507, and  travelled to Floor 0508 with Alit and Topknot; while the Master and Missy had told Nardole and Hazran that they intended to find a means of stopping the "scarecrows" and their creators, as well as a means of escaping the Mondasian colony ship, the Master secretly intended to reverse the Twelfth Doctor's edit to the Cybermen's definition of humanity and regain control of the cyber-army on Floor 1056.

After travelling through the superstructure walkways between Floor 0507 and Floor 0508, the four rode a service-cradle to the latter floor, before spending most of a day following and riding numerous pieces of advanced farming equipment, until they eventually reached a large network of warehouses and storage silos. A patrol of CyberNeomorphs then confronted the Master, Missy and Alit, whose Cyber-Leader declared that the patrol had been sent by their Cyber-Planner to Floor 0508 to capture the Master and Missy for interrogation concerning the change to the Cybermen's definition of humanity. Following the Cybermen to the lifts, the Master and Missy attacked the Cybermen before they could imprison them in a storage cell. The Master destroyed the Cyber-Lieutenant with his laser screwdriver before being rendered unconscious by the Cyber-Leader, while Missy and Alit escaped.

Inside a storage barn, Missy quickly stunned several mice and constructed several wire cages to store them around hers and Alit's necks; the close proximity of three heartbeats confused the Cybermen's life sign scanners long enough for Missy and Alit to escape to a weather control tower, after recovering Topknot and leaving him to guard at ground level. At the top of the tower, Missy hacked into the colony ship's systems and stopped the Cybermen's secondary plan to attack Floor 0507 with a swarm of Cybermats; by reactivating an old failsafe system in the Cybermats that was also incorporated into all the Cyber-Technology on Floor 1056, Missy trapped the Cybermat swarm at the bottom of the colony ship. She then altered the weather settings for Floor 0508, generating a huge rainstorm, before leaving with Alit and Topknot.

Returning to the lifts, Missy used Topknot to distract the Cyberman - sacrificing him in the process - and rescued her predecessor from the storage cell, before Alit returned with three pairs of gumshoes. After putting them on, the trio escaped the silos but were attacked by the Cybermen. The Master then fired his laser screwdriver at the steel deck of the floor; due to the ongoing rainstorm, this generated a huge electrical blast which disabled all the nearby electronic machines and electrocuted the Cybermen. The Master, Missy and Alit then rode an automated grain lift back to Floor 0507. On their way back, Alit questioned Missy as to why she chose not to stop the other Cybermen on Floor 1056 with the failsafe system as well, but Missy dismissed the idea, still conflicted as to whether she was allied with her previous incarnation or the Doctor. (PROSE: Alit in Underland)