Grant Ward's betrayal of the team at the end of the first season proved to be the biggest surprise in the short history of the show. The character had been built up from the beginning as a disciplined and dedicated agent of SHIELD. After his fall, and the death of his mentor, he was imprisoned by Coulson and held until he was given over to his brother and quickly escaped. What makes Ward an interesting character is that his true motivations are unknown. He has stated previously that he was loyal to Garrett and not HYDRA. Now that he is teaming up with Agent 33 (who looks like a scarred version of his previous lover), he can either cause havoc for Coulson, form an uneasy alliance in order to take down HYDRA at the end of the season, or both.