# V: Disappearance of a Scientist explained — The Big Four

> Chapter companion for The Big Four by Agatha Christie.

## What happens

After the trial of Robert Grant, Poirot and Hastings receive a visit from Inspector Japp and Captain Kent of the US Secret Service, who reveal that a scientist named Halliday has disappeared in Paris. Halliday was working on a powerful wireless energy device that the Big Four may have used to sink American naval vessels. Poirot agrees to investigate and visits Mrs. Halliday, who confirms her husband vanished after a trip to Paris, leaving behind only a small suitcase. Poirot decides to go to Paris to find the truth.

## Themes in this chapter

### Global Criminal Conspiracy

The Big Four's international plot to dominate the world is revealed through their use of advanced wireless technology to sink naval vessels.

### Science and Technology as Weapons

Halliday's research on concentrated wireless energy is weaponized by the Big Four, demonstrating the destructive potential of scientific innovation.

### Intelligence and Deduction

Poirot uses logical reasoning to connect Halliday's disappearance to the Big Four, dismissing the police's simplistic theories.

## Character check-ins

### Hercule Poirot

Investigates Halliday's disappearance, deduces the Big Four's involvement, and decides to travel to Paris.

### Captain Hastings

Narrates the chapter, expresses frustration with Poirot's passive approach, and accompanies him to visit Mrs. Halliday.

### Inspector Japp

Brings Captain Kent to Poirot and provides information about Halliday's disappearance.

### Captain Kent

US Secret Service agent who shares details about the Big Four's wireless weapon and Halliday's expertise.

### Halliday

British scientist who disappeared in Paris; his work on wireless energy is linked to the Big Four.

### Mrs. Halliday

Halliday's wife, who insists her husband was devoted to his work and did not leave voluntarily.

## Key lines

> He is an artist, this one. He disguises himself not with the false beard and the blue spectacles. He alters his features, yes; but that is the least part. For the time being he is the man he would be. He lives in his part.

Poirot explains that the criminal mastermind is a true artist of disguise, not relying on props but fully embodying his roles.

_Reflects Poirot's admiration for the adversary's skill and the theme of deception._

> The Big Four are for themselves⁠—and for themselves only, M. le Capitaine. Their aim is world domination.

Poirot states that the Big Four seek global control, acting solely for their own benefit.

_Highlights the global conspiracy theme and the organization's ultimate goal._

> He cared for it more than he did for me.

Mrs. Halliday says her husband loved his scientific work more than their marriage.

_Emphasizes Halliday's dedication to his research, which the Big Four exploited._

## Links

- HTML: https://www.betterreads.online/discover/the_big_four_se/chapters/v-disappearance-of-a-scientist
- Book: https://www.betterreads.online/discover/the_big_four_se
- All chapters: https://www.betterreads.online/discover/the_big_four_se/chapters