An "escape game" activity is proposed to increase stimulation, team group skills, and adaptability in the chemistry classroom. The students follow in the footsteps of Nicolas Leblanc, a young French chemist, who took part in a contest launched by the French Academy of Sciences in 1775 to produce industrial soda ash. By means of scientific puzzles, such as using the periodic table, balancing a reaction, drawing up a flowsheet, or performing simple mole calculations, students will access combinations of numbers that allow them to open mechanisms present in the room that give them access to other enigmas. Following a precise sequence (controlled by the teacher present in the room), the students will thus advance in groups by retracing the development of one of the first industrial processes in the world. Escaping from the room is not the end of the activity: a debriefing will highlight the key elements of the construction of this process and will indicate the resources for further research, notably on the environmental consequences of the Leblanc process and the passing of the alkali act, one of the first laws to limit atmospheric pollution in the world. To simplify the principle of classical "escape games", a classroom version, based on an easily printable paper sheet and locked file folders, is proposed in this paper.