End of the Beginning is the sixteenth episode of the first season of the television series Agents of S.H.I.E.L.D.
Agents Garrett and Triplett are back to help Coulson's Team track down S.H.I.E.L.D.'s nefarious enemy - The Clairvoyant. But will Deathlok destroy them all to protect his master's identity?
John Garrett and Antoine Triplett are attacked by Mike Peterson, who had been reborn as Deathlok, at a S.H.I.E.L.D. safehouse. Several weeks later, they along with Agents Victoria Hand, Jasper Sitwell and Felix Blake join Coulson's Team in their hunt for the Clairvoyant.
The agents split into teams to pursue leads on different Clairvoyant candidates. At a nursing home searching for Thomas Nash, a catatonic man who once claimed to be a psychic, Melinda May and Blake encounter Deathlok. Before critically injuring Blake and escaping, he claims that "Mike Peterson is dead" upon being reminded of his son.
However, Blake manages to tag Peterson with a tracker before he fled. Concluding that Nash is the Clairvoyant because of Deathlok's presence, along with the falsifying of his nursing home records, the team converges on Deathlok's next location, an abandoned horse racing track, while Triplett and Jemma Simmons stay behind at the Hub with Hand.
The team briefly encounters Deathlok again, but he flees into the sewers. They discover a hidden room where Thomas Nash, a vegetative man on life support who could only speak through a computer, is hiding. Nash surrenders and boasts that as the Clairvoyant, he would always be watching them. When he says that the Centipede Project would kill Skye, Grant Ward instantly shot him dead.
Meanwhile, Leo Fitz attempts to create a secret phone line so that he could speak to Simmons from the Bus. While there, he discovers a bug that lead him to May's secure line. Phil Coulson realizes that Thomas Nash is not the Clairvoyant. When Skye presents the results of her studies on the S.H.I.E.L.D. psychological files of the potential Clairvoyants, they realize that the Clairvoyant is a member of S.H.I.E.L.D., with access to the same files. This gives the Clairvoyant knowledge of how to manipulate the agents.
Coulson accuses the detained Ward of working with the Clairvoyant, and shooting Nash to direct them away from the Clairvoyant's true identity. They are interrupted by Skye, who had learned of May's unapproved phone line from Fitz. Coulson and Skye end up in a standoff with May in the Bus's hangar. As May tries to explain that she was not allowed to identify to whom the line went, control of the Bus is hijacked.
At the Hub, Victoria Hand orders that everyone aboard be killed, except for Coulson, claiming, "He's mine."