Agents of S.H.I.E.L.D. Season 1 Episode 19
The Only Light in the Darkness
When Audrey, Coulson's one true love's life is in danger, he uses some of the team to keep her safe. When it is revealed that the man after he recently escaped from The Fridge, the connection between Audrey and Phil is revealed.
When May leaves Providence, it leaves Eric, Skye, and Ward alone. When Skye and Eric come up with a plan to hack the NSA satelite to get footage of the fridge's break in, Ward kills Eric.
After some searching, Skye finds Eric dead revealing to her that Ward is indeed HYDRA. She then plays along with his game to figure out a plan of her own while the team is away.