Chasm Forge Chasm Forge was a class A7 mining station owned by Ganymede Systems . It was built to mine copper ore at some point in the far future after humanity had become a spacefaring species . After receiving a distress call , the Twelfth Doctor went to the station with Bill and Nardole . ( TV : " Oxygen " ) Design . Chasm Forge was built on top of an asteroid from which it mined resources . The station itself was circular and made up of several sections connected together by circular rings . The station was connected to the asteroid by a single central support column . Conveyor s were used to mine the asteroid . The station housed a smartsuit repair bay , central nuclear core and dormitories . ( TV : " Oxygen " ) Crew . Chasm Forge originally housed a crew of forty . Upon the Doctor ' s arrival , only four life signs remained . These were those of Tasker , Abby , Dahh - Ren and Ivan . Ivan ' s wife Ellie was also part of the crew , although she died prior . ( TV : " Oxygen " ) Technology . Chasm Forge was designed as a mining station powered by a central nuclear reactor . Its computers were controlled by an onboard artificial intelligence called Velma . She monitored communications , the airlocks , th oxygen supply , the smartsuits and had many other functions . The smartsuits on board Chasm Forge possessed mechanized exo - skeletons that meant they could take control and function automatically , without there necesarily being an occupant present . When put a user the exo - skeleton would wrap itself around the user ' s limbs and the rest of the suit would teleport onto the occupant . The suit formed an invisible force field around the user ' s head to provide them with oxygen . However , these shields were not strong enough to endure the vacuum of space . Collapsible helmets were thus provided along with the suit to remedy this . Magnetic soles were built into the heals of the suits ' boots to allow them to walk on the outside of the station . The suits were equipped with a number of tools such as welding lasers to perform various maintenance tasks . Each suit was connected to the onboard AI and could receive remote commands . If ordered to , the suits could " deactivate their organic components " . This meant killing the occupant by emitting a lethal electric shock that fried the person ' s nervous system . On hand , the personnel of Chasm Forge had laser pistols and rifles that were used to defend themselves . ( TV : " Oxygen " ) History . Chasm Forge was built on top of an asteroid in order to mine copper ore by Ganymede Systems , a spacefaring organization . At had a crew of forty workers , each equipped with a Ganymede Systems Series 12 smartsuit , and an onboard AI . After several months , the crew became less and less productive and the station was declared non - profitable . The Ganymede Systems board of directors thus sent the AI an instruction to " deactivate the organic component " of the smartsuits . This meant killing the crew , as they were deemed to expensive to live . All but five smartsuits received the instruction and the crew were promptly killed until only crew members Ivan , Tasker , Abby , Ellie and Dahh - Ren were left alive . They were spared as their suits were off - network when the command was sent . In an attempt to transmit a distress call , Ivan and his wife Ellie ventured outside in order to hook up their suits ' radio to an antennae . They were unsuccessful and as they made their way back inside , Ellie was ambushed by two smartsuits that ripped her helmet off , exposing her to the vacuum of space and killing her . Though Ivan was horrified , he managed to get back inside and barricaded himself in a section with the remaining crew . The Twelfth Doctor , Bill Potts and Nardole picked up the distress call and landed the TARDIS on board Chasm Forge , only to be quickly forced to don smartsuits as there was no oxygen except inside the suits . They were chased by the smartsuits and eventually made their way to the remaining crew . Hoping to get back to the TARDIS to evacuate the survivors , they were forced to go outside the station . Tasker and Dahh - Ren were killed along the way . But due to Bill ' s suit malfunctioning , the Doctor was forced to give her his helmet and was exposed to the vacuum of space , blinding him . After Bill was seemingly killed by the smartsuits , the Doctor , Nardole , Ivan and Abby went to the station ' s nuclear reactor core and hooked up their vital signs to it , rigging it to blow if they were to die . Upon hearing this , the onboard AI calculated that Ganymede Systems would make the biggest loss ever and deemed the survivors more expensive dead than alive . They were thus spared and the Doctor revealed Bill was in fact alive as her suit did not have enough power to lethally shock her . Following these events , the Doctor transported Ivan and Abby back to Ganymede Systems ' headquarters in order to inform the public . Six months later , a successful revolution took place and the company was permanently shut down . ( TV : " Oxygen " ) Shadow World . In the Shadow World , a virtual reality designed by the Monks to be a perfect copy of the Doctor ' s universe , simulacra of the Twelfth Doctor , Bill Potts and Nardole had recently returned from Chasm Forge . The Doctor had been blind ed as a result of his trip there . ( TV : " Extremis " )