Gael Manfretti was one of an active loyalist who is now part of the resistance.
Manfretti unexpectedly enters the lab, Etta captures him. Olivia later figures out he just wanted to feed the pigeons. Etta questions him about the science building, using a device that ages a person many years in a few seconds. It's Observer tech that the Loyalists adapted to use on the resistance. The torture bothers Olivia, but Etta says he doesn't deserve sympathy. Wanted to escape Manfretti made up a story to Olivia that he had a family at home and the reason he joins the Loyalist is because of "pain" after a resistance action killed his oldest son. He thinks humans have no chance, and if the resistance stopped fighting, the world would be safer.
Privately, Olivia agrees that if Manfretti cooperates, she'll tell his son he's never coming home and that he loved him very much. He says the science building contains the main power grid, but rumor has it the Observers use it for experiments "on everything." He gives them his access code, and Walter fashions a substitute for Manfretti's eye from a preserved pig's eyeball, so Peter and Etta can fool the scanner.
Etta prepares to take Manfretti to the resistance. Olivia is uncomfortable, knowing he will die. Etta says he doesn't have a son; he lied in hopes that Olivia would free him. Olivia says she sees what the Observers brought to Etta's world. But she's more concerned about what they've taken away. At an unknown location, Manfretti admits that Etta was right: He doesn't have a son. He became a Loyalist because he's a coward. When Etta lets him go anyway, he vows to join the resistance.
Something in Olivia's eyes made him feel, for the first time, that the humans are supposed to win. Etta's letting him live because she saw something in Olivia's eyes too: pity, for all of them.