|First seen||"Let the Games Begin"|
|Last seen||"Let the Games Begin" (Alive)|
"Speak of the Devil" (Corpse)
|Series lifespan||"Let the Games Begin"|
|Portrayed by||Mare Winningham|
|Family||Maxine Seagrave † (daughter)|
|Status||Dead (Let the Games Begin)|
|Cause of Death||Drowned|
|Agatha Seagrave Gallery|
- "You think the world is just looking out for you, don't you? As if whoever and whatever is behind that curtain is pulling strings just for you. There's nothing behind that curtain but darkness."
- —Agatha to Big Jim.[src]
Before the DomeEdit
Agatha was born by the name Claire. She attended Chester's Mill high school, in the same high school as Big Jim Rennie. Claire had to drop out of school at 16, when she became pregnant with her daughter, Maxine.
Claire could not get work, and resorted to prostitution to take care of her daughter. She was labeled as a whore and a pariah by the men of Chester's Mill. Bitter over the town's hypocrisy, as she was publicly shamed by some of the very people who paid for her services, she changed her name to Agatha.
Sometime before the dome, Agatha moved to a mansion on Bird Island, owned by her and Maxine, who became "crime lord" and used her money to take care of her aging mother. Agatha was Maxine confidant, privy to her daughter's illegal activities. She knows everything about the Chester's Mill drug operation and everyone involved.
Under the DomeEdit
Big Jim looking for Maxine's "insurance policy", arrives at Maxine's island house. Agatha recognizes him and pretends to be only a caretaker claiming it belongs to Oliver Luckland who is currently on his boat on the other side of the island. She invites him inside to wait for him to return, and when he's unsuspecting, holds him at gunpoint.
Agatha told Jim, her former classmate, about her history and connection to Maxine. She angers Jim when she taunts him about his son, Junior becoming as crazy as his dead wife. Big Jim dares Agatha to shoot him and when she comes closer, he manages to disarms her. Jim then realizes that Agatha is Maxine's "insurance policy" and decides to take her with him to Chester's Mill. Along the way back, Agatha falls into the water. She pleads for Jim to save her, but he leaves her to her fate.
Sometime later, her body washes ashore and is found by Maxine.
|Season 1 appearances|
|"Pilot"||"The Fire"||"Manhunt"||"Outbreak"||"Blue on Blue"|
|"The Endless Thirst"||"Imperfect Circles"||"Thicker Than Water"||"The Fourth Hand"||"Let the Games Begin"|
|"Speak of the Devil"||"Exigent Circumstances"||"Curtains"|
- Agatha's last name is "Seagrave" which is ironic because her grave becomes the water. She pretends that her house owned by a man called Oliver "Luck-land", which is quite the polar opposite of Sea-grave, while the house is owned by Maxine real estate company named "Osiris", which is also the Egyptian god of the afterlife.