Beckett's team investigates an ice cream man's murder and find evidence that a child may have been a witness, so Castle goes undercover at a local school's 2nd grade class to find them.
Tropes that appear in this episode:
- Bait-and-Switch: Castle thinks one kid who wrote about a giant with a gun was the witness, but it turns out to be something he saw on TV. He then plays tea time with another girl, Emily, who seemingly had something she didn't want to talk about, but she just wanted to tell Castle that Jason was her bully. In the end, none of the kids were the witness. It was actually Jason's older sister Natalie, which Castle and Beckett find out when Jason slipped his drawing into Castle's coat pocket.
- Chekhov's Gun: Jason wanted to show off his Polaroid camera on Castle's first day in the class. It turns out he took the camera from his sister Natalie, who had earlier used the camera to take a picture of the killer.
- Chekhov's Skill: Castle takes down Prokovnik by dumping marbles on the floor, just like Jason did to him earlier.
- Practically Different Generations: Jason is an eight-year-old second grader, while his half-sister Natalie is an adult old enough to be teaching classes at a local community college.
