Specialist Campbell was a Sentinel who participated with Alpha Team in the Sentinels' first mission in Alaska to retrieve an atomic bomb from the Chimera. During the journey to Alaska, Campbell possessed some degree of medical knowledge and was even aware of the fatality of secondhand smoke from learning from British Doctor Richard Doll. Also, for some time, Campbell had been trying to write letters of recounting his experience under Project Abraham and the Sentinels to his mother. Although, it is noted that it was impossible to send the letter based on the military's Code of Zero Tolerance from disposing the secret of the Sentinels and other classified topics from the public.
Just after surviving a Kraken attack that sunk the ship Alpha Team were in, the team decided to march. It is there that Campbell was fatally shot in the head by an Chameleon while writing his letter concerning on the survival of his mission. His body (and his letter) was decidedly left behind by Alpha Team to continue on to their mission.
- Campbell is the first 'proper' Sentinel to be killed.
- He is known as a specialist which is an E-4 in the Army and means he is not an NCO