Colonel Bosh was a senior officer of the United States Department of Homeland Security's Specified Counter-Insurgency Unit.
He and his team took an abnormal that Dr. Helen Magnus' Sanctuary team had just hunted down and brought it to Area 51, unknowingly allowing Henry Foss to track them all the way. When Magnus and Will were caught in the facility while Henry was trying to hack the system, Bosh and one of his agents brought them to Nikola Tesla.
Sometime later, he witnessed an agent get captured by an abnormal that came through an energy rift. He was able to escape from Area 51 before things got worse.