Cauchemar Cauchemar was a human geneticist who was exiled to a prison colony on the New Earth frontier . His crime was experimenting on fellow colony members in a quest for immortality . Although his efforts made his cells capable of dividing almost endlessly , they mutated . As Cauchemar was being taken to prison , his ship was damaged and some of the prisoners took over certain functions to keep the ship going . Cauchemar fell in love with his warden , Jasmine , in the process , but she could never love him knowing what she did about his past . The ship passed through a spatial anomaly that damaged the cells of the crew . They were contacted by beings of pure energy who had elevated themselves to this level of existence after discovering the gene for the soul . They wished to dispose of their criminal element . Cauchemar engineered the humans into carriers , living prison cells for the aliens ' criminal souls , but created a symbiotic relationship so the human souls would share in the testing and be able to achieve communion with the Universe , monitored by the Holiest , beings genetically engineered from the dead to pass the judgment of the " Creator " , the controlling program . However , Cauchemar ' s experiments upon himself had rendered him unsuitable as a host and the aliens ' offer of freedom was no longer enough without Jasmine . Cauchemar was expelled from the world , but found his way back and became involved with the " reincarnation " of Jasmine , even though he knew that his intervention — and , indeed , his eventual offspring — would taint the gene pool , creating humans who went around with nothing but their own baggage , rather than a recreated soul getting another shot at life . Cauchemar ' s transition through space had also left him fatally ill , causing his immortal DNA to collapse in piles of sludge . When he tried to save himself by taking genetic samples from " Jasmine " , she was badly injured . He tried to take her to the water mountain s where the Creator existed , hoping that the Creator would aid him for making this world possible , but the Creator could not perceive Cauchemar and its defences unmade Jasmine ' s DNA . His closeness to Jasmine allowed Cauchemar a moment of bliss as her entire life was made known to her . Cauchemar wished for the chance to know himself . He built devices with stolen genetic equipment to save himself . All they did was put off his own inevitable death , even as he refused to let the world he had created go on without him . Taking advantage of the fact that the Creator could only detect the colonists containing the godswitch on chromosome 13 , Cauchemar lobotomised colonists . He removed the aliens ' essence to make them invisible to the Creator . Served by these , he searched for years for the colonist who reincarnated Jasmine . Finally , Cauchemar — now calling himself Derran Sherat — believed he had found Jasmine ' s soul in a woman called Treena Grace . He had a child with her after he also had a son with Treena ' s sister , Ettianne . To force the Creator to accept him , Cauchemar genetically engineered a baby with the fingers of colonists he had murdered . As their flesh still lived in the baby , their godswitch es — the DNA that let them know the meaning of their lives — were never thrown . He intended to kill the baby close to the Creator . This would release the built - up potential energy of all the experiences within it , disorientating the Creator . He would further overwhelm it by murdering the inhabitants of the planet ' s sole city with a network of bombs . The resultant self - defensive frenzy of the Creator would cause a feedback of energy into the remaining colonists , killing everyone carrying the godswitch , and preventing any more of the alien souls being released , while Cauchemar killed Jasmine ' s current host and rode into Heaven with her . Treena discovered his plan and was disgusted by it . Cauchemar concluded that her lack of understanding " proved " she couldn ' t be Jasmine . He allowed her to die during a botched bank robbery when she tried to kill him . He turned his attention to Ettianne — who guarded the " mooncalves " , individuals lacking a godswitch and born deformed due to Cauchemar ' s past interference in the planet ' s development . He sent his agents to collect her . They failed when the Doctor , Fitz and Anji arrived on the planet by chance and interrupted the abduction . Aided by Nathaniel Dark , one of the Diviners — people who worked out the meaning of peoples ' lives when they didn ' t die natural deaths — the Doctor concluded Derran Sherat was the key to the puzzle . It was too late to stop Cauchemar ' s agents capturing Ettianne ' s son Braga to force her to come to him . The Doctor took Ettianne ' s place . He confronted Cauchemar and recovered Braga after learning his true history , but Ettianne was captured by Cauchemar during their escape and taken to the Creator ' s mountains . The Doctor realised Cauchemar had " named " his followers according to grids and locations on the city ' s map . He deduce d that the people were named for the places they would set off their bombs in the final attack on the Creator . As one of the men had been killed during Ettianne ' s capture , he thought that Cauchemar ' s right - hand - man , Hox , would take his place . The Doctor dispatched Fitz , Anji and Dark to stop Hox while he and the mooncalves went to save Etty . In the confrontation , Hox was killed , destroying Cauchemar ' s plan — his followers could not set the bombs off themselves . The infant was killed while the mooncalves got Etty to safety . As Cauchemar ' s body finally fell apart , he tried to kill the Doctor by dragging him into the water with him , but , as Cauchemar died , the Doctor put himself into a healing coma , allowing his body to drift until Fitz and Anji could recover him . ( PROSE : " Vanishing Point " )