Duke is a Tier-One Citadel agent who operates in support of the Tier-One team led by Mason and Nadia. During the mission to infiltrate the Hasan’s Research Facility in the Alborz Mountains, Duke provides air cover for Mason and Nadia as they battle Hasan’s operatives on the ground. During the Red Cell Mission to install a bypass device on the Russian Submarine, Duke offers level-headed technical support to Mason.