The night after Halloween, tree girls, strapped with a video camera and scared in anticipation of the mythical Glasgowman, head into the woods to find this mysterious urban legend. However, only one of them makes it out.
One young girl was stabbed and hospitalized, while the other two - a sister, and a friend - remain missing.
Benson is brought up to speed, and arranges a babysitter for baby Noah in order to join the search.
The two girls slept at Perry's house, and all of their phones seem to be purposefully left at Perry's home when they went out to the park.
Zoe, the youngest girl went along with her older sister's and Perry's plan. And now, as the only survivor she needs to recap the events of the previous night.
Mia, her older sister, along with Perry, tricked both parents in order to seek out the Glasgowman.
Zoe claims to have seem the assailant's face - the Glasgowman, with a scar from ear to ear, and an eye path.
A search through the park leads to a man living in an alcove, who charges the police with a stick. They taze and apprehend the suspect.
Caresi one-ups Amaro and gets to interview him with Benson. Together they try to drive a confession out of the man, but the disturbed individual may actually be innocent.
Charlie Dorsey, the man in the woods, claims to not be responsible for the missing girls. He exhibits symptoms of many different psychological disorders such as multiple personalities, schizophrenia, and bi polar disorder. However, he is adamant in his assertion that he only found Zoe bleeding and helped her.
The squad head to Charlie's home in the woods to find a hidden recording equipment he said he stole, but instead they find bloody knifes. Charlie claims the knifes are for hunting, but its suspicious.
Zoe lied to the police because of a "pact," with the other girls, and didn't mention the Glasgowman's "mansion," the portals, a map, and so forth.
Perry's babysitter, Leslie, apparently gave the map to children. The squad go to interrogate Leslie.
Glasgowman is based on Charlie, but Leslie was just creating a lore, a work of fiction. He creates graphic novels.
Leslie's drawing of the map leads the squad to the "gateway" to the "mansion," where they find both the girls barely breathing.
Perry's story doesn't seem to be adding up (no defensive wounds, says she was attacked last night), and the girls claim that Charlie is indeed Glasgowman.
Charlie was in custody and couldn't have done what their timeline indicates.
It starts to be revealed that Mia and Perry may be lost in their own fantasy world, not able to differentiate reality from fiction, and may have been trying to harm Zoe.
Perry stabbed herself, after tying up Mia, and hurt Zoe as well.
A psych evaluation of Perry was conducted. She seems completely deluded by the lore.
She is sent to a psychiatric center.