Agents of S.H.I.E.L.D. Season 1 Episode 16
End of the Beginning
Agents Garrett and Triplet are attacked by Deathlok when they arrive at their safe house. In response, SHIELD decides to go on the offense in the search for the Clairvoyant. Skye is made an Agent of SHIELD and given the responsibility of coming up with a list.
The agents move on targets when they come across Deathlok again. Blake shot Deathlok with a tracker and the team goes after him. They find Thomas Nash and believe he's the Clairvoyant. He taunts them and Ward kills him.
Skye and Coulson realize that Nash was a plant. The Clairvoyant is someone inside SHIELD. When Fitz finds May's secure line, Coulson believes she's involved. Agent Hand orders the person controlling the plane to take them all out, except Coulson.