Father Andrew Doyle was a Roman Catholic priest who served as a missionary in foreign countries to bring the word of God to the people. While serving in South Africa, he used his church to also hide refugees, mostly children and families, from the guerrilla groups fighting in constant civil wars. One guerrilla came into the church in search of suspected rival guerrillas (but were, in fact, two children and a young woman). Knowing he was going to kill the family if he got the chance, Andrew shot him and the guerrilla died. Because of his sacrilegious act, and the fact he never took a life before, he was constantly wracked with guilt and left the country some time later, and returned to his home in Los Angeles.
When the First Invasion began, Andrew joined the Resistance group under Julie Parrish's command. He was willing to go into battle and, using his experience in Africa and other hostile nations, proved himself to be a capable soldier and helped his fellow rebels on a variety of missions. He still continued his religious duties, such as performing sermons, "last rites" ceremonies (for terminally injured rebels), eulogies at funerals and other religious services. He also had a secret desire for peace with the Visitors as he saw the entire war as a waste of life.
When Elizabeth Maxwell was born, Andrew grew afraid of the increasingly hostile attitude by many, even her own grandfather Robert Maxwell, towards the girl. He also began to see her as living proof of the possibility of peace he desired and considered her a miracle of God. When Robin used the experimental Red Dust on Elizabeth's father, Brian, Andrew's fears reached its breaking point and took the girl, left the base they were staying and willingly turned himself in to the Visitors. For delivering the girl to her custody; Diana gave sanctuary and proper accommodations to Andrew, and with orders for him to be treated like a guest, rather than a prisoner. When Andrew, who expressed a desire to carry the word of God to the people of Sirius 4, gave his bible Diana to examine, Diana drew unexpected conclusions by reading it and, thinking the book's beliefs have pointed out her weaknesses, killed Andrew in front of Elizabeth. Andrew was also one of the Resistors that assisted unmasking John on television.