In 1935, when his train is stopped by deep snow, detective Hercule Poirot is called on to solve a murder that occurred in his car the night before.

The defense and the prosecution have rested and the jury is filing into the jury room to decide if a young Spanish-American is guilty or innocent of murdering his father. What begins as an open and shut case soon becomes a mini-drama of each of the jurors' prejudices and preconceptions about the trial, the accused, and each other.