Dunn's early life was unknown, but he attended University of Oxford and presumably excelled in technology and computer science. One of his professors was Doctor Wickham, whom he described as "fat and big", and learnt biomolecular kinetics and cellular dynamics under his tutelage. At some point, Dunn joined the IMF as a technician and befriended Ethan Hunt, telling him the story of Wickham scaring freshmen students regarding how technology would eviscerate the world In 2006, Dunn helped Hunt analyze information from a stolen laptop. He also seemed to hold some knowledge of Rabbit's Foot, which he speculated as a "anti-god" with mass destruction capabilities akin to a doomsday device, as black arms dealer Owen Davian was chasing after to sell to the highest bidder After being captured by the IMF for being accused of being a mole, Ethan escapes and goes rogue, and calls Benji for help. Benji guides Ethan through the streets of Shanghai, to save his wife, Julia Meade-Hunt. He succeeds in helping him locate Julia, and Ethan states that he owes him a drink