LeDuc was a professor of Theology and an agent of the Torchwood Institute. He entered into a romantic relationship with the alien Gabriel and claimed to have attended an airshow at the Grand Palais in Paris in 1909.
He travelled to Paris on a mission to locate Project Hermod, pretending that Gabriel was his son. On the way, they visited Montroy. He met Berber and had himself captured by Hans Grau, who tortured him for information on Torchwood. (AUDIO: The Dying Room)