Big MT The Big Mountain Research and Development Center , alternately known as Big MT or the Big Empty , was a privately owned pre - War defense contractor and research center located in the Southwest Commonwealth . It serves as the game - world for the " " " Old World Blues " . Background . Origins . The Big MT Research and Development Center was originally built inside a cave system running underneath a large mountain peak that gave it its name . The goal of the facility was to build the future of mankind and create the technology of tomorrow without restraints , either moral or technical . It welcomed some of the most gifted pre - War scientists , who plumbed the depths of many experimental technological fields . The research conducted within was as groundbreaking as it was unethical , conducted in part on living humans ( both American volunteers and Chinese - American detainees ) . Big MT even included a concentration camp of its very own , safeguarded by lucrative contracts with the US Army , such as the X - 42 giant robo - scorpion . However , due to budget cuts in the later years of its operation , Big MT had to improvise alternate means of funding and research . The executives began to strike deals with third parties , exchanging experimental technology for money and other privileges . Due to budget cuts , they even began assassinating non - military targets ( Project Hare ) to procure research subjects , and exhuming buried US citizens ( Project Burke ) to procure test subjects . Due to a failed experiment conducted in the Y - 0 research center , the mountain above the center was vaporized , leaving behind a giant crater and exposing the facility . This catastrophe later became known as the Great Static and did not faze the researchers , and the efforts in pushing the boundaries of science continued unabated . The new land exposed by the explosion was adapted for scientific purposes : new facilities were established , both above - and below - ground , including an artillery test field and a test town . The facility was under the guidance of its six gifted executives , 0 , 8 , Borous , Dala , Mobius , and the administrator , Klein ( their original names unknown ) known together as the Think Tank . The facility gave birth to new technologies , such as the Saturnite alloy , next generation hazmat suit s , new models of cyberdog s , advanced stealth suits , s , and many more . At the same time , many new horrors were also born in the laboratories of the Big MT : cazador es , night stalker s , mutagenic plants , ambulatory corpses , previously unknown toxins , and other fearsome creations . Both types were sold to private parties in exchange for certain favors : Frederick Sinclair obtained various experimental technologies ( including even the prototype matter conversion machines ) in return for allowing Big MT to use the Sierra Madre as a proving grounds , a decision that backfired catastrophically when the experimental technologies turned on the casino inhabitants , dooming them . Such an event was not unprecedented either , as the town of Hopeville was wiped off the map by a disastrous meteorological experiment in another such exchange , and later became the Divide . The scientists ' cooperation wasn ' t entirely frictionless . During one particularly heated dispute with Doctor Mobius , Doctor Klein threw the Sink ' s personality chips off the dome ' s balcony . The Big MT staff picked up the various holodisk chips and stored them in existing facilities , and that of the Sink Central Intelligence Unit was personally recovered by the future Doctor Klein . The Great War and its aftermath . When the Great War came , it did not stop the research efforts ; it merely put them on a different rail . Mobius worked on predicting the post - holocaust economic systems . A new project was also started , with the purpose of preserving the Big MT " Think Tank " executives by transforming them into a special brain bot named after their group , allowing them to continue their work at Big MT indefinitely . With no body to stand in the way , their research continued , becoming more sinister and debauched as the years went by . Eventually , the remaining human staff dispersed into the wasteland or were killed off by increasingly out - of - control experiments ; like the escape of the cazadores and night stalkers . Only the six think tank s remained in the Big MT . Mobius , tired of the think tank ' s endless and horrible experimentation , thinking that " the world isn ' t ready for that kind of too - far - thing - taking " and , believing that the think tanks had finally lost what remained of their humanity , erected a radar fence - a kind of radar - guided repulsive field - around the perimeter of Big MT to prevent the disembodied brains from escaping into the wasteland , and destroying what little remained of humanity with his colleagues ' planned experimentation on a new " fertile testing ground . " After a severe dispute with Klein , Mobius hacked his colleagues ' shells , causing them to forget large portions of their personality and substituting their name with a new one , reinforcing the recursion loop already programmed before . Furthermore , he hacked the databanks of his colleagues , reprogramming their chronometers , geometers and cartography programs , essentially erasing their sense of time and history . He also forged several facts to focus the Think Tank ' s attention on himself : that his robo - scorpions consume intelligence from brains ( creating the fear to go outside the central Big MT ' s dome ) , that he was exiled for crimes too heinous to remain in recorded memory , and a belief that Big MT is all that remains of the world , that nothing exists outside . In the end , his tampering created mangled , disjointed versions of his former colleagues . Disgusted by his actions against his friends , he erased some parts of his own memory to ease his conscience , such as this event ( though not permanently , as certain phrases could reawaken the memories ) and knowledge of his pre - War creation , the robo - scorpion . Soon after , Mobius removed himself to the X - 42 robo - warfare facility ( renamed the " Forbidden Zone " ) , where he began to " re - create " the robo - scorpion , inspired by radscorpions wandering into Big MT . His new creation retained all features of the pre - War model : a tail - mounted energy bolt blaster , eyes systems allowing him to see through them , remote control and public address systems allowing him to monitor the Big MT . Fearing that the radar fence would not be sufficient to hold the mad scientists inside the crater , he set up a repeating threat message to be broadcasted to the Think Tank . The aim was to instill fear and prompt them to focus on retrieving technologies that would allow them to depose Mobius . When Big MT finally fell silent , it became the arena of an increasingly demented , insane struggle between Mobius and the Think Tank . The latter remained inside the dome , ever fearful of their self - appointed warden and his scorpions . Big MT had few visitors , the sheer size of the crater serving as its best camouflage : most wastelanders assumed the ragged edges to be remnants of a massive nuclear explosion and avoided it altogether . The unfortunate few who wandered in disappeared forever , apprehended by robots and lobotomized by the think tanks to act as organic automata , maintaining the decaying facility and protecting it against scavengers . Over the years , it became known in the wasteland as the " Big Empty , " a place where nothing exists . Its size and aura of mystery blocked the establishment of trade routes and reliable supply caravans between the Boneyard and New Vegas , a fact that proved crucial for the survival of Caesar ' s Legion immediately following the First Battle of Hoover Dam , as the NCR was unable to reinforce its army quickly enough . The Visitors . Even though the facility ' s security was almost perfect , three people were able to elude the think tank s and survive the horrors intended for them , before Courier Six arrived : Elijah , Ulysses and Christine Royce . Elijah came to the Big Empty in search of weapons that would allow him to destroy the NCR and everyone who would oppose him in the creation of a new Brotherhood of Steel order . Elijah scoured the facility for technologies that would be of use to him in his endeavor . Namely , after learning of the Sierra Madre from Ulysses , he started gathering equipment that would allow him to crack the casino . The most important and sinister of these were the concentration camp detainment collars , that he experimented with during his stay . He also took an unusable holorifle prototype , perfected afterwards thanks to the holograms of the Sierra Madre . Ulysses came to Big MT in search of knowledge , to learn what makes and breaks nations , what would allow him to reawaken America , the Old World . He also went to the Big Empty to study weather patterns , as he left his mark on the X - 17 meteorological station . Christine Royce followed Elijah , tasked with killing him for the crimes committed against the Brotherhood of Steel . Of the three , Christine was the only one who did not escape unscathed . Captured by Big MT robots following a disastrous skirmish at Little Yangtze and pitted against Elijah who sent the survivors of Little Yangtze against her like walking bombs , she was subjected to horrific experiments in the Y - 17 medical facility conducted by some Mister Orderly and Y - 17 trauma override harness es and with a Mark IX Auto - Doc . These experiments permanently damaged her brain , destroying her ability to read and write fluently . She was saved from certain death by Ulysses , who destroyed the entities and nursed her back to health in his camp in Big MT . Afterwards , he talked to her about philosophy and his desire to go into the X - 17 meteorological station and speak with the Think Tank . At some point after Elijah spoke with the Think Tank , this made the Think Tank doctors question their ideas regarding the world . The Think Tank began to doubt that their world was as small as they had perceived , bringing new ideas to their minds . After Ulysses and Elijah made contact , at which point Ulysses directed him to the Sierra Madre , Ulysses too spoke with the Think Tank , particularly Dr . Klein , who asked a lot about history . Ulysses asked a dangerous question : " Who are you , that do not know your history ? " After Ulysses showed them the Old World flag , the Think Tank eventually remembered many past events , especially that there is a world outside the Big Empty , a world with ideas and possibilities for experimentation . Dr . Klein regarded the question as too dangerous , and , as it reminded him too many past events , he subsequently deleted it from his memory . After coaxing the answers he wanted out , Ulysses returned to his camp to say farewell and pass on information to Christine about Elijah , and he left Big MT to travel onward to the Divide . Elijah was the only one who left the Think Tank a parting gift . After being apprehended by Dr . 0 and Dr . 8 , he hacked them both within minutes , permanently damaging 8 ' s voice module and leaving destruction in his wake . He left Big MT on a cargo train , and then crashed the remaining trains in tunnels leading out of the facility . During these events , Mobius observed , even the conversation of Ulysses and Elijah with the Think Tank , rendered the inability to act on anything , and his fears grew surrounding the future actions of the Think Tank . Some time after the three left permanently , the Think Tank installed a pacification field in the Think Tank central area , preventing anyone without a brain to have hostile impulses . Afterwards , to see if there really was something outside of Big MT , they sent a satellite prototype with a unique charge of teleportation outside of Big MT which crashed in the Mojave Drive - in in the Mojave Wasteland . It emitted a signal in the form of a jazz theme named mysterious broadcast that led to it . The Courier arrived , just after having been guided by the signal , inspected the satellite during the night and triggered the unique teleporter on board the satellite , transporting themself to the Big MT . Afterwards , the Courier was taken to the Sink in preparation to become a lobotomite ; but due to the gunshot wound from Benny causing a cranial injury in just the right place , it was enough for the Sink Auto - Doc to change its programming to fix the problem , improving the cranial extraction procedure . However , in the process , it was necessary to replace the spine and heart with synthetic organs . With the Courier ' s brain procedural data , the Think Tank would be granted the knowledge to modify their cranial selves into hosts to slip past the radar fence and leave Big MT . However , after the Think Tank extracted it , they degraded into bickering amongst themselves . Mobius saw an opportunity to steal the Courier ' s brain with its knowledge and led it into the " Forbidden Zone . " Wanting to escape with brain intact , the Courier was obliged to help the Think Tank against Mobius by retrieving three pieces of technology , changing the future of Big MT forever . Layout . Big MT is dominated by the central dome named the Think Tank , which is connected to outlying facilities by numerous walkways , pipes , and conduits . To the north lies the rail line that passes into Big MT via the Big MT north tunnel before splitting into two lines that run toward the east and west tunnels . Near the north tunnel is the X - 42 robo - warfare facility , an important facility even with a dome ; later known as the " Forbidden Zone , " the lair of Dr . Mobius . Other notable facilities include the Signal Hills transmitter , the Saturnite alloy research facility , the X - 22 botanical garden , and the X - 17 meteorological station . Just north of the western train tunnel is the Little Yangtze concentration camp and the construction site . To the east , along the eastern rail spur , lie several notable facilities , including the X - 8 research center , the X - 7b " Boom Town " target zone , the securitron de - construction plant , the hazmat testing ground , and the waste disintegration platform . The western portion of the crater is dominated by the X - 66 Hexcrete archipelago , a collection of hexagonal concrete structures that vary in size from small platforms to towering monoliths . Among the hexcrete structures are several facilities , including the X - 13 testing facility , the Z - 43 innovative toxins plant , the Z - 38 lightwave dynamics research building , and the X - 7a " Left Field " artillery launch . In the southern portion of the crater is Higgs Village , which contains the former homes of the Think Tank within a large , hangar - like structure . It is flanked by the X - 12 research center and Y - 17 medical facility . This is not an exhaustive list of locations within Big MT , but notes some prominent facilities visible from the balcony of the Sink , Dr . Mobius ' s former apartment , located atop the central dome . For a complete list of locations , see Locations in " Old World Blues " . Inhabitants . Originally meant as a beacon of new hope for humanity , Big MT eventually created a vast number of horrifying , unique creatures and machines , several of whom have made the Mojave Wasteland their home and killing grounds . Big MT ' s " legacy " includes : Appearances . The Big Empty is mentioned in the " " " Dead Money " , " Honest Hearts " , and " Lonesome Road " and appears in the add - on " Old World Blues " . It was to appear in " Van Buren " , but in later development was merged with the Leavenworth Prison into the Tibbets Prison facility . Tibbets would occasionally still be referred to as the Big Empty by developers in design documents . Behind the scenes . The Big Empty is one of two known facilities to have done research on electrical weapons . The other was the Secret Vault , Vault - Tec ' s private vault .