Russ Dante, a seventh-grade math teacher with Asperger syndrome, is painting the sunset at Elver Park when he sees one man stab another to death. The next day, the body is gone, and Russ is a suspect. Russ works to solve the murder, but he needs to hurry, because the killer saw him and now wants him dead.
Asperger Sunset contains examples of:
- Bavarian Fire Drill: Before Russ returns to Meadow View to learn the identity of the person who replaced him in his room, he puts on a lab coat from his college years and the ID card he wears as a teacher, which looks like a Meadow View ID card unless you look closely. At the facility, he makes an illegible scribble on the sign-in sheet and strides briskly down the hall with his hands in his pockets, politely returning any greetings people offer. No one questions him.
- Cessation of Existence: Russ refers to his parents as "completely, totally nonexistent."
- Cool Kid-and-Loser Friendship: Russ's childhood friend Zach Hunter was one of the popular kids. Russ would help Zach study, and Zach would defend Russ from bullies. When they hung out, the other kids treated Russ like a friend.
- Cope by Creating: Russ paints the sunset partly as a coping mechanism for his anxiety.
- Flashback Nightmare: The morning after the murder, Russ wakes up sweating and gasping from dreams of the murder.
- Inevitable Waterfall: The killer throws Russ off a bridge just upriver of a dam. Russ fails to get to shore on time, but manages to get through a sluice without drowning.
- Interrupted Suicide: Russ impulsively tried to cut his wrist three months ago because of his grief over his parents' deaths in a boating accident. His younger sister Misty found him in the garage and took him to the Meadow View Mental Health Facility, where he recovered. After he witnesses the murder, Russ checks himself in again in the hopes that the tight security will protect him from the killer.
- Recovered Addict: Zach used to have substance abuse problems. Eventually he got clean and became a priest, and now he counsels addicts.
- Sensory Overload: For the most part, Russ doesn't like going outside because he finds the sights and sounds overwhelming.
- Switching P.O.V.: Between Russ and Misty.
- Tantrum Throwing: A doctor gives Russ an Asperger's checklist where all the questions begin with "Does your child…" Russ feels like he's being treated as a broken child and is so offended that he throws the clipboard against a wall.
- Working with the Ex: Misty is forced to let her ex Adrian Bowman, who never got along with Russ, help investigate.
- Your Makeup Is Running: When Angela, the victim's girlfriend, cries and rubs her eyes, she leaves streaks of makeup across her cheeks. Later, when she holds Russ and Baldy at gunpoint and demands to know which of them killed her boyfriend, her face is streaked black with mascara.