First published as La Chiave a Stella by Einaudi in 1978, the book was written after Levi had retired from the family paint business SIVA.

The scene is loosely based upon Togliattigrad, the Fiat camp set up in Russia to build a car factory.

The job of a rigger is to set up cranes and scaffolding and to manage major mechanical projects.

One of Faussone's jobs is to sort out a problem with an acetic acid separation column which goes through a cycle of making loud noises and shaking, before settling down again.

The story, one of many in the book, is about troubleshooting, and the forensic investigation skills needed to solve industrial problems.