He fully immerses himself in their world, playing with army men and wearing fairy wings for tea parties.

A second-grade student reportedly witnessed the crime, leading Castle to go undercover at the school to identify the child.

⭐ While the procedural plot regarding Russian mobsters is somewhat cliché, the episode succeeds as a character study of Castle’s eternal "inner child." Castle Season 7 Episode 4 Review: Child's Play - TV Fanatic

The episode begins with the murder of an ice cream truck driver named Anton, who was caught in the middle of a high-stakes conspiracy.