Weary, the narrator returns home. She goes to her room and lies down but is too fatigued and overwrought to sleep. Too tired to think about her own story, she thinks about Moira's.
The narrator has pieced it together from different people's accounts—Alma, Dolores, Janine, and Aunt Lydia.
The narrator imagines how the information initially came out, which was when Aunt Lydia took Janine into her office and confided in her. The narrator didn't like Janine much, but she was still an ally on some level.
Aunt Lydia would have told Janine that Moira had escaped.
Moira had asked for a bathroom break. She called out to Aunt Elizabeth, who was on guard, that the toilet was overflowing.
When Aunt Elizabeth came in and went to take a look, Moira threatened her with a weapon she'd made out of part of the toilet, forcing her to give up her weapons and go downstairs into the furnace room. There, Moira changed clothes with Aunt Elizabeth, gagged her, and tied her up. Dressed as an Aunt, Moira walked out of the building and out into the world unchallenged.
The narrator makes up an interchange in which Moira told Aunt Elizabeth to be grateful that she hadn't killed or tortured her before walking out.
Aunt Lydia asked Janine to report on any possible news, and while none of the other women really trusted Janine, they were grateful for the news she gave them about Moira.
Janine probably told Dolores, who told someone else.
The narrator and other women at the Center became envious and scared of Moira, but they also lived vicariously through her. They worried she would be captured and punished, but as of this point in the story, the narrator hasn't heard anything about her showing up again.