One second, the four girls are in handcuffs and chains, arrested as accessories to Mona's murder, which the police believe Alison carried out; the next, they're waking up in replicas of their own bedrooms. They go out into the dark hallways where they wander to another room and find Mona. For the past five months, everyone thought she was dead, but it turns out that she's been forced to "play" Alison in an underground dollhouse, blond wig and all. She's being watched on-camera and must follow the rules or be starved, as well as forced to listen to an ear-shattering siren and audio of her friends and family crying at her funeral.
Although the person watching Mona thinks that they've broken her, she reveals to the four girls during the three-minute generator reboot that she plays along to survive but hasn't lost herself. Mona knows the exit to escape but can't figure out how to do it in those three minutes before the doors lock.
Later on, Hastings figures out that random block letters in "her room" spell out Charles and believes that's the person behind all of this.
It's prom night at the dollhouse, and Charles chooses the same theme from Spencer's sister's prom. The five girls come up with and execute a plan to shut off the electricity and manage to get out of the dungeon dollhouse, but not before Spencer comes in contact with a masked Charles and senses eerie familiarity.