George is a man with Down syndrome who lives with his mum, his seventeen-year-old half-sister Susan, and his stepdad Adam. As a Christmas present, Susan receives a video game called Nephilim Caves, the first game with sentient characters. As the weeks pass, Susan develops more and more of an emotional connection to the game's hero, Oemor, who is programmed to be in love with her and is on a quest to rescue a character based on her from captivity, and longs to communicate with him for real. Meanwhile, George wants to move into his own apartment and marry his girlfriend Tracy, who also has Down syndrome, but both face opposition from their families.
Like a Fish Understands a Tree contains examples of:
- And I Must Scream: Oemor hates when Susan pauses the game because he's trapped immobile.
- Basement-Dweller: George's mum is adamant that he will never move out.
- Disappeared Dad: George is the product of a teen pregnancy. His mum raised him by herself until Adam entered the picture.
- Fantasy-Forbidding Mother: George's mum believes that the idea of two adults with Down syndrome living independently is an impossible fantasy, and blames the recreational center for planting the idea in his head.
- Gory Deadly Overkill Title of Fatal Death: The company that produced Nephilim Caves took Oemor's code from a character in their earlier game, Megadeath.
- Grew Beyond Their Programming: Oemor eventually learns to fight the joystick and move independently.
- Masturbation Means Sexual Frustration: George masturbates in his room while he thinks about Tracy. He's never been given any sex education — he only knows that he wishes Tracy could be there while he does it, and maybe even touch him, but he's worried she'd find it rude.
- My Beloved Smother: Mum believes George is too "special" to do various things he wants to do, like get a job and play computer games for adults.
- Named Like My Name: Susan's last name is Sarandon. She's embarrassed by it, and annoyed that her parents didn't realize they'd named her after a movie star.
- Never Learned to Read: George can't read. To his frustration, he's still required to "read" magazines with everyone else as one of his activities at College.
- Parent with New Paramour: When Mum and Adam first met, Adam played football with George and unsuccessfully tried to teach him math. His apparent friendliness was only due to his belief that George's intellectual disability could be "fixed" with proper parenting. Once Adam realized that George was never going to be any more normal, he mostly ignored him.
- Reverse Arm-Fold: The teachers at Susan's school always clasp their hands behind their backs when they talk to students so they can't be accused of touching them.
- Say My Name: Oemor screams "SUSAN!" every time he dies in the game.
- Sleeps with Both Eyes Open: Susan falls asleep with her eyes open in class. She's usually awakened by the bell, too late to understand what the homework assignment is. When she first arrived at her new school, she would ask the other kids, but now they don't want to talk to her.
- That Cloud Looks Like...: George's bedroom is in the attic, with a window over his bed. He likes to look through it and look for shapes in the clouds.
- Their First Time: George and Tracy finally get to move in together. On their first night, George doesn't know what to do, so Tracy shows him.
- Title Drop: "George understood writing like a fish understands a tree. It cast a shadow over areas of his life, he knew it was there, and he could do nothing about it."
- Welcome to Corneria: Susan, George, Tracy, and Oemor finally beat the game together, and Oemor finds the cavern where the NPC Susan is being held. However, she can only say "Oemor my love? Is that you? Have you come to save me? Oemor my saviour set me free so I can once again return to my land and my dear father," over and over again. Oemor, who has gotten to know the real Susan through her entries in an in-game journal, is devastated by how different "she" is in person.
