Sarah was born to Charles and Emily Harper in 1988. Charles Harper worked for British Military Intelligence from 1991 until his death in an overly zealous interrogation in 2002 by the CIA. It was suspected that he was passing secrets to the Iranians and although never cracked under interrogation his heart stopped as a result of electric shocks. This killing, though never proven, caused a large personal rift between members of the British secret service and the CIA. Until this point Sarah had lived a quiet and happy comfortable middle-class upbringing in London. She was a superb schools athlete and academic pupil. She was 14 when her father died, the explanation given was a heart attack while away on business (technically correct). The loss of her father scarred Sarah very deeply and she spent her mid-teens losing focus of her promising academic career where she gave into drinking and mild drugs. Since the death of Charles she and her mother had been surveilled by Charles’ former boss and friend Simon Cross. He was deeply hurt by what had happened to Charles and what his death was now doing to his family. For this reason Simon created an alias for himself and infiltrated the Harpers lives. He did this initially by wooing Emily the widow with his considerable charm and they married in 2004 making Simon, or more precisely his alias, Sarah’s step-father. Simon took notice of Sarahs problems, doing much to remove any bad influences from her life. He saw huge potential in her athletically, she seemed to have almost limitless stamina and he encouraged her into martial arts training. Simon spent a great deal of time with Sarah and began to obsess about her. His marriage to Emily was an act but he began to develop strong feelings for the daughter and before long they began an affair. This was a considerable betrayal by Simon who at first had transplanted himself into Charles Harpers life and was now taking advantage of his teenage daughter. The betrayal stretched beyond him also with Sarah enthralled by this man but also wracked with guilt about betraying her mother. It was clear to Simon that Sarah had the skills to become an agent and so shortly before her 18th birthday he revealed that he worked for MI6 and nothing more.
She gained entry to the service on his say-so and was given extensive combat and weapons training. Her job was to infiltrate Elite Force and report back her findings. She managed to get inside the training program when it was slowly discovered that her athletic prowess and stamina was more to do with a super-powered ability than simply good genetics. It turns out that Sarah has a ‘Second Wind’ in fights, allowing her to completely replenish all energy whenever she is near defeat. This is a tremendous survival power as it gives her the opportunity to get away from danger or finish a difficult job. She became torn over whether to keep reporting against Elite Force, when in reality she is more like them than any secret agency could have believed possible.