In 1927, as part of a publicity stunt that was to inaugurate a new daily paper, the Paris-Matinal, Simenon signed a contract in which he agreed, for the sum of 100,000 francs, to be locked inside a glass cage outside the Moulin Rouge.

As early as 1953, Simenon described in an interview conducted by the Paris Review that his method of composition, which required "depersonalizing" himself and completely entering into the mindset of his characters, caused him a great strain, which became almost unendurable after a week of writing, and was, by his own admission "one of the reasons my novels are so short."

Like the main character Émile in The Glass Cage, Simenon also suffered from headaches and dizzy spells, and soon after completing work on the novel, his ailments became severe enough that checked in to a clinic for treatment.

Unable to establish a positive relationship with anyone in the society in which he lives, Émile feels like a stranger everywhere, and displays a profound indifference to the world as long as it does not intrude upon his daily schedule.

The reassuring monotony of their lives is interrupted when Émile's sister Geraldine informs him that her husband Fernand is cheating on her, and that he has asked for a divorce, though for the sake of their three children, she has refused to go through with it.

The newlywedded couple have recently moved into the building; François works as a sales representative and so is frequently travelling and not at home.

[6][7][8] Writing for Books Abroad, Lucille Becker describes The Glass Cage as a "fascinating psychological study.