# IV explained — Monsieur Lecoq

> Chapter companion for Monsieur Lecoq by Émile Gaboriau.

## What happens

Lecoq and Father Absinthe painstakingly track the footprints of the two women from the Poivrière crime scene through the snow, using plaster casts to preserve evidence. Despite losing the trail at the Rue du Chevaleret, Lecoq deduces the fugitives hailed a cab and resolves to find the driver the next day. Meanwhile, local vagabonds witness the detectives' lantern moving eerily across the plain, mistaking it for a will-o'-the-wisp.

## Themes in this chapter

### Deduction and Scientific Observation

Lecoq's methodical tracking, use of plaster casts, and reasoning about the cab demonstrate scientific deduction.

### Appearance vs. Reality

The vagabonds mistake Lecoq's lantern for a supernatural phenomenon, while it is actually a tool of police investigation.

## Character check-ins

### Monsieur Lecoq

Leads the investigation, makes plaster casts of footprints, and deduces the fugitives escaped by cab.

### Father Absinthe

Assists Lecoq in tracking footprints, collecting boxes and boards to protect the casts.

### Gevrol

Mentioned indirectly as part of the authorities expected to arrive at the scene.

### Widow Chupin

Her drinking den, the Poivrière, is the site of the crime; vagabonds hear shots fired there.

## Key lines

> What luck! the experiment was successful! The plaster united in a homogeneous mass, forming a perfect model of the impression.

Lecoq's plaster cast experiment succeeds, creating a perfect replica of the footprint.

_Highlights Lecoq's innovative forensic method._

> I understand! I comprehend—I see! ... these tracks explain everything.

Lecoq realizes the fugitives escaped by hailing a cab that turned around at that spot.

_Key deduction that advances the investigation._

> Upon the unoccupied tract of land ... a small but very bright light was seen describing the most capricious evolutions.

Vagabonds see a strange light moving erratically on the plain, which is actually Lecoq's lantern.

_Illustrates the theme of appearance vs. reality._

## Links

- HTML: https://www.betterreads.online/discover/monsieur_lecoq_se/chapters/iv
- Book: https://www.betterreads.online/discover/monsieur_lecoq_se
- All chapters: https://www.betterreads.online/discover/monsieur_lecoq_se/chapters