was a trooper
under Lieutenant Scott
who ventured into a cave
system to investigate the disappearance of seven members of Professor Kyle
's arcahelogical expedition.
After Walters lost contact with Baines, Collis and Snyder, Sergeant Mitchell took Bailey and Carter to investigate.
After Carter found Snyder's remains, two Cyberman androids ambushed them, killing Bailey, Carter and Mitchell. (TV: Earthshock)