During the war, Sir Finch was placed under house arrest in his Sussex manor for his fascist sympathies. Hegley was put in charge of the guards enforcing his house arrest. However, Finch's charisma and his history with Hegley allowed him to convert the officer to his cause. The other guards eventually followed suit and Finch regained control of the manor, with Hegley acting as his butler.
Hegley remained unnerved by Finch's behaviour and his occult rituals, and continually questioned his loyalty to him. He was especially tested after learning that Finch had murdered the cleaner girl, Sally, but ultimately, Hegley never wavered. Eventually, Finch grew to trust Hegley enough to invite him to become part of his rituals
After the Third Doctor, Jo Grant and Wing Commander Douglas Quilter of the London Controlling Section foiled the plans of Finch and Daisy Chapel, Hegley and the rest of the surviving collaborators were arrested by the British Army. The Doctor expressed that Hegley had let everyone down, including himself, by passing up every opportunity to do the right thing before the fascists were defeated. (AUDIO: Operation: Hellfire)