Monk invasion The Monk invasion of Earth lasted for a period of just over six months , in which the people of Earth were brainwashed into believing an alternate history : a history in which the benevolent Monks had both guided human evolution and guarded them from threats as powerful as the Dalek s , Cybermen and Weeping Angel s . ( TV : " The Lie of the Land " ) Overview . Preparing to invade . To prepare for the invasion , the Monks used a simulation known as the Shadow World to track humans and to choose the exact right moment to invade . The Veritas , an ancient text , contained the truth about the simulation , which would cause the person to commit suicide to free themselves from it . The Veritas was kept in the Haereticum , a library of blasphemy in Vatican City . In 2017 a translator emailed a translation to various locations , including CERN before killing himself . The simulacra of the Pope called the simulacra of the Twelfth Doctor , Nardole , and Bill Potts . In the library Bill and Nardole found a portal to a room full of projectors , while the Doctor read the Veritas but was found by the Monks before he could finish . Meanwhile Bill , and Nardole stepped through a portal and found themselves in CERN where the personnel were about to destroy the building with themselves inside . Before the building exploded , the personnel had them say random numbers , but strangely each time , they said the same number because of the computer nature of the Shadow World . They returned to the room before they were killed , but Nardole was deleted when he stepped out of the light of the projectors , while Bill made her way to the Oval Office in the White House where the president had killed himself by taking a drug overdose . There she found the Doctor , who told her the truth behind the Shadow World . Horrified she denied this but the Monks then deleted her from the simulation . The Doctor then used his Sonic Sunglasses to send an email of his experiences to the Twelfth Doctor titled " Extremis , " to him before the Monks deleted him too , tempting him to release Missy from the Vault . Awaiting consent . The Monks then landed the Cathedral in Turmezistan where the American , Chinese , and Russian armies were about to meet . Suspicious , the Secretary General contacted Bill Potts , Nardole , and the Twelfth Doctor to investigate . A monk then exited the pyramid and reveled that they required consent to invade , and then caused every clock in the world to start counting down to its destruction . They attempted to attack the pyramid , but they failed . The Monks showed them inside the simulation chamber where they reveled that there would be a World War III like event in the future . The Secretary General offered his consent , but detecting that his decision was based out of fear the Monks disintegrated him . When the American , Russian , and Chinese made peace to stop the event , it did not stop the clock . The Doctor then went to Agrofuel Research Operations , where a chain of events created a bacteria that threatened all life on Earth . Working with a lab worker named Erica , they created a bomb to wipe out the bacteria , but the Doctor got stuck inside with the bomb , prompting Bill to give her consent for them restoring his sight . The reign of the Monks . The Monks then moved the Cathedral to London and erected statues of them in every major city , and used Bill ' s brainwaves to broadcast a version of Earth ' s history to brainwash people that was transmitted by the statues . They also forced the Doctor to broadcast their corrupted version of history on TV for them . However the Doctor was secretly plotting against them . Bill managed to find the Doctor with the help of Nardole where he pretended to side with the monks before reveling himself . They visited Missy to see how to defeat them but was told that the effective method was to fry Bill ' s mind and leave her permanently brain - dead . However the Doctor devised another way by hacking into the transmitter and broadcasting the real history of Earth . When the Doctor tried , the Monk controlling the transmitter rejected him . Bill then tried , to fry her brain like Missy suggested . At first the Monk just used her to strengthen their hold over Earth . However Bill used her memories of her mother to fight back , as the Monks could not touch the uncorrupted memories of her . The images of her mother were transmitted to every person in the world , breaking their hold over Earth . The Monks then evacuated in the Cathedral and erased themselves from the memories of everyone on Earth .