Cavanaugh appeared in the original screenplay draft for the movie Highlander: The Final Dimension. Cavanaugh was an early attempt to get a new teacher and friend for Connor MacLeod. That role, however, was taken over by Nakano in the final draft.
Cavanaugh was already nine centuries old, when he met Connor MacLeod in the late 1600s. He was a good friend of his former teacher, Ramirez. Cavanaugh became good friends with Connor, too. He once gathered all local Immortals on Holy Ground. He spoke with them about The Prize, its importance, and why it should be won by a person of good intent He asked them to teach what they had learned to other Immortals.
Cananaugh would encounter Connor again later. He told him to start living, rather than drifting across the world, which is what MacLeod had always done up to that point.
By the year 1786, they had their last encounter. Together they traveled to France aboard a ship, where Cavanaugh and Connor were captured by republicans during the French Revolution. Cavanaugh was beheaded by the guillotine, his Quickening was received by Connor, who managed to escape in the distraction.
In the year 1986, Connor's wife Brenda, was hit by a car and brought to a hospital in New York City. Connor was then haunted by visions of people he had met in his life, among whom was Cavanaugh.