The events take place during the fall of 1993 and 1994.

In 1993, a flashback is shown of Kate going to Martin's house for the first time. A number is shown "Day 1" on screen.

In 1994, the therapist explains to Kate how Martin groomed her. Scenes are shown from 1993 where Martin is helping Kate and watching her over while she's sleeping. The therapist explains that the false sense of security that Martin built between Kate was a trap.

In 1993, Kate sees the basement for the first time. In 1994, she reveals to the therapist that she wasn't always locked in the basement.

In 1993, Joy and Rod are worried about Kate not coming home from the last night. At Martin's house, he informs Kate that he likes their friendship, but she needs to call him "Mr. Harris" at school. Mallory records the sprinkler prank from outside.

While Martin is out, Kate is exploring through Martin's house. Later, Martin is frustrated that Kate didn't go to school after she burns a frozen pizza; he wants her to go home so that he won't get into trouble for lying.

Martin receives a call from a detective that worries him. Martin tells her that she's been a reported as a missing person. Kate is worried and asks him what they should do.

Kate wants them to take their mind off the police report. She pitches them to play Never Have I Ever.

In 1994, Kate thinks the stress was on their friendship, but the therapist doesn't think their power struggle was a friendship.

In 1993, Martin reveals he went on a roadtrip and drinks. Martin asks Kate if she kissed someone significantly older than her; she says no, but they flirt about toying with the idea. In 1994, Kate tells her therapist that Martin made her feel seen.

On Day 21, Kate and Martin are playing hide and seek. A fun montage is shown of playing, kissing, and having a great time. While Kate runs them a shower, Martin panics after seeing a news report about her being missing.

On Day 30, Martin encourages Kate to pick a travel destination for them to go on her 18th birthday. Kate wants them to move away together; she's considering Thailand or Morroco.

On Day 34, Kate talks about Renee's parents having an age difference. Greg Turner abruptly visits to use his phone about his flat tire. After he leaves, Martin panics and hangs a sheet over the door so no one can see them.

On Day 64, Kate and Martin are prepping for Halloween; Martin tells her that everyone believes she ran away from town.

In 1994, Kate tells the therapist that Martin made her choose between him and the outside world. She chose him for a long time.

In 1993, Kate asks Martin what the future holds for their relationship bubble. In 1994, Kate reveals she was tired of having in-house conversations.

On Day 89, Kate asks about her parents, but Martin doesn't tell her anything. She's not happy about the stuffing or the situation. A voiceover reveals that by Christmas Eve she was feeling homesickness.

In 1993, Kate tells Martin that she misses the outside world and things about her life, like her mom, pretzels, and watching movies.

Martin goes to the mall for Christmas shopping; Jeanette sees him and rides her bike away. Martin panics when the police arrive at the mall, but they run past him.

Kate makes the phone call to Jamie while Martin is out. She's watching the movie and playing with the snow globe, but she doesn't talk on the voicemail. Jeanette opens the door with her key and JKate goes running to hide.

Jeanette calls out, but no one answers back. Jeanette takes the snow globe and leaves after she hears a sound; she accidentally drops her necklace behind. Kate picks up the necklace and keeps it a secret from Martin. A voiceover reveals Kate kept it as a secret so that she held some power against Martin. The therapist thinks it was a hope mechanism that she wanted Jeanette to see her and tell everywhere where she was.

Kate tells her therapist that she did leave Martin's house once to see her parents through the window. After she runs away, Rod and Joy talk about their sadness of not having Kate around; they hope Kate returns to them soon.

A voiceover with her therapist reveals that Kate remembered why she came back to Martin; it was the wounds that were opened up by seeing her parents.

On Day 119, Kate and Martin are opening up gifts; Martin gives her a pearl necklace. During dinner, Martin confronts Kate about her lying and sneaking out.

In 1994, Kate tells her therapist that this dinner was the first time she truly felt afraid of Martin.

In 1993, Martin chastises her for going outside before she turned 18. Kate is sad and tells him that she wants to leave; she says she won't tell anyone that she stayed at Martin's house. He begs her to stay, but she wants to leave.

She heads to the basement to grab her suitcase. Martin locks her in the basement; he plays music to drown out Kate's banging on the door.