What happens after hours at Le Bon Marché Rive Gauche? Shoppers will have the opportunity to find out on Friday and Saturday nights starting Sept. 2, as the department store plans to offer a cycle of immersive theatrical productions in honour of its 170th anniversary.

“The occasion is an opportunity to talk about our history, and doing so through a play felt self-evident,” said Frédéric Bodenes, artistic director of the Left Bank retail institution. For the base material of the narrative for “Au Bonheur des Dames,” he looked to the eponymous 19th-century novel written by French author and politician Émile Zola and loosely based on the success story of Bon Marché founders Aristide and Marguerite Boucicaut.

Within 45 minutes of the store’s 7:45 p.m. closing time, 250 spectators will be welcomed into the store for a celebratory cocktail that will soon take an unexpected turn that will take them back to 1862 and the fictional department store described by Zola. Bodenes didn’t want to spoil the plot but did allow that it would explore an episode of the novel in the manner of a whodunit, “like the board game ‘Clue,’” where the audience will be invited to gather clues and offer their solution to the mystery. The musical score will be performed live, as 40 actors live out 12 tableaux throughout the 150-minute playtime. Guiding the audience through the story — and the store — will be French journalist and radio host Fabrice Drouelle, whose voice has become associated by Francophiles with the true crime and trial show “Affaires Sensibles” (or sensitive cases, in English) on public radio station France Inter.

For those distracted by the decor or their fellow sleuths, missing a clue won’t prevent you from leaving the store, as Bodenes promised “this is no escape game.” But don’t expect to be able to shop the latest styles after hours. The immersive play will be one of the highlights of a four-month anniversary celebration, which kicks off in September and continue until the end of the year. For spectators who don’t speak French, an Anglophone version is also in the works, although details were still being finalized. Tickets will be priced at 75 euros and retail through French ticketing services accessible through Le Bon Marché’s events page.