Plot summary

The Hardy brothers interrupt their investigations of jewelry store holdups to answer a plea from their cousin on a New Mexico cattle ranch. They discover how Arrow cigarettes can knock people out using a gas that comes out from a vent in the ground in New Mexico, originally discovered by American Indians.

Original edition (1949)

• Ghostwriter: Andrew E. Svenson
• Summary: The boys travel to their cousin's ranch in New Mexico and crack a ring of thieves who knock out their victims using gas hidden in cigarettes.

Revised edition (1970)

• Revision type: Minor revisions.
• Ghostwriter: Priscilla Baker-Carr