Operative from Serenity meets Decker from A-Team, member of Harper's old team
Theta Unit was a close knit team of the US Army Rangers. With Todd in charge, and Harper his second in command they quickly became the go-to team for unusual mission. When Todd was promoted out of the field, and Harper chose to leave the military Joseph Wilson was given command of the team.
He was certainly a well proven member of Theta and after performing above expectations on a relatively easy first mission (for Rangers anyway) the higher ups believed that despite losing the top two members Theta’s combat effectiveness was unhindered. This was unfortunately not the case as on their second mission half of team was wiped out.
Wilson took this extremely hard and fell into drink, before having his act pulled together by another survivor of Theta who now worked for the DIA (Defense Intelligence Agency). When the order came out for Harper to be tracked and killed for stealing secrets Wilson jumped at the chance, now shifting the blame he carried around the Theta’s death to Harper abandoning the squad when they needed him most.