Whisperer Gamma (Thora Birch) reveals her real name when attempting to cut a deal with Aaron (Ross Marquand) in a scene from The Walking Dead's midseason finale, "The World Before." Aaron first encountered Gamma in 10x05, "What It Always Is," when he showed kindness and supplied her with bandages. In 10x07, "Open Your Eyes," Aaron attempted to connect with the masked Gamma, showing him a drawing from daughter Gracie (Anabelle Holloway) and encouraging her to open up about her past — including sore subject Frances (Juliet Brett), killed by Gamma when the loyal acolyte saved leader Alpha (Samantha Morton) in 10x02, "We Are the End of the World."
During a meeting at a Whisperer border, Gamma asks Aaron if her nephew — the baby Alpha forced Frances to abandon outside Hilltop in 9x11, "Bounty," who was first rescued by Connie (Lauren Ridloff) and later adopted by older couple Earl (John Finn) and Tammy Rose Sutton (Brett Butler) — is still alive.
Asked if the boy was ever given a name, Aaron gives away as little as possible, telling Gamma he was christened Adam. When Gamma asks if she can see Adam, Aaron tells her, "Your people left him to die. Why would we ever agree to that?"
"Because we can trade," Gamma answers. "I have information for you." Before she gives it, Gamma wants Aaron to promise she'll be able to see the child, but he says any deal is dependent upon the validity of Gamma's intel.
"He's the only family I have left," Gamma says. Aaron tells her to start with the truth, and to do it without the mask. "Before all this," the newly anointed Gamma says, "my name was Mary."
Gamma's about-face comes after learning Alpha's daughter is alive, a revelation that left Gamma distraught: the Whisperers were told Alpha killed Lydia (Cassady McClincy), with only Beta (Ryan Hurst) and Dante (Juan Javier Cardenas) knowing the truth.
"It is absolutely crushing to Gamma when she sees Lydia standing there," executive producer Denise Huth said on Talking Dead. "Gamma has been a true believer. She's been very loyal to Alpha and to the Whisperers. She believes in this, she believes this is how they survive. So much so that in episode 2 we see her kill her sister for the sake of protecting Alpha."
"She sees what her sister is about to do and she doesn't hesitate, she just does it, because she believes in Alpha so very much. And so to see Lydia alive and well and standing there, and knowing that she's been lied to, it makes all of it seem like a lie," Huth continued. "It makes her question every decision she's made, and what she's done, and why she's done it. You killed your sister to protect this woman who blatantly lied to you, what else is she lying about?"1comments
Gamma could disclose Alpha is harboring Alexandrian fugitive Negan (Jeffrey Dean Morgan), who escaped jail with the help of a so-far unidentified accomplice. Alternatively, she could expose Dante as the Whisperer spy within Alexandria's walls.