The Doctor[]
The doctor is a wonderful addition to a team of players, as the special is the ability to heal or revive one teammate per mission. However, the Doctor cannot heal themselves. To use the special, make sure there is nothing in your hands, go to the injured or downed player, and hold "F" until healed. You can also press "H" to drop your doctor box, which will allow any teammate to pick it up and heal themselves. There is no passive ability for the Doctor.
