Jasper Sitwell was a Level 7 S.H.I.E.L.D. operative and member of HYDRA. Sitwell was indoctrinated into the ranks of HYDRA, for whom he took on a role as a double agent within S.H.I.E.L.D. Several of his missions involved extraterrestrials and demigods. During the years of service he became a good friend with his fellow agent Phil Coulson. Overtly, he conducted his duties with efficiency, while covertly he aided a deep-rooted conspiracy to reshape the world in HYDRA's image. Eventually, his true allegiance was uncovered by S.H.I.E.L.D. agents Captain America and Black Widow, who kidnapped him and forced him to reveal the truth behind Project Insight, shortly after which he was killed by the Winter Soldier.