- "Thank you, Agent Coulson, for all your help."
- ―Lewis Seaver to Phil Coulson
Lewis Seaver was a former S.H.I.E.L.D. agent.
Agent of S.H.I.E.L.D.
The man now known as Lewis Seaver was a S.H.I.E.L.D. agent who was asked in 2009 to be a part of Project T.A.H.I.T.I. by Phil Coulson after "Seaver" learned that he was dying. Like the five other participants of the project, "Seaver" was injected with GH.325 and his fatality was cured; however, like the others he became inclined to write the alien symbols and was slowly going insane. Coulson conferred with Dr. Goodman and she suggested using the Memory Overwriting Machine to erase his past memories and give "Seaver" a new life. As part of the new life, the participant was given the name Lewis Seaver. 
Though Seaver had a new life, the inclination to write the alien symbols was still in him. In 2015, he wrote the symbols on the back of a painting in Santa Maria de las Flores, a church in Miami.  Lewis was approached and killed by Sebastian Derik, another participant in Project T.A.H.I.T.I. before Phil Coulson shut it down. Derik burned the church and Seaver's body.  Only the painting remained unscathed.
Skye did research into the name "Lewis Seaver" when it was given by Phil Coulson during a session in the Theta Brain-Wave Frequency Machine. Coulson was using the machine to remember the names of the six agents who were in the project. Skye learned Seaver's fate and told Coulson such as she asked him for more names so that they could save others from Derik's killing spree.
- Sebastian Derik - Fellow T.A.H.I.T.I. Patient and Killer