In fiction the cauldron or crucible is a setting or situation that forces characters to change or make difficult decisions; to face what they’d rather not face.

I’ve written about cauldrons before and mentioned how they must be inescapable. Two powerful examples come to mind–the islands in Lord of the Rings and Jurassic Park. Let’s return to this concept for a minute. I lived in Milwaukee, Wisconsin in the 1970s and 80s. During these decades the heavy machinery factories were starting to close down and the blue collar jobs started disappearing. For a few years I lived on the south side of town and nearby was a huge foundry. I can still remember summer evenings driving or pedaling past when the workers would be outside on break. The furnaces were deep orange and scarlet against the darkening skies, sparks flying, shooting high,  the mens’ black, sweat-streaked faces, slumped shoulders, the whole thing like something out of Inferno. The place radiated with not only heat, but also danger, toil, and misery. 

Do you know how real-life crucibles work? It’s a technique started centuries ago. It’s the furnace or container for molten metal where the iron ore, for example, is placed under extreme heat to liquefy. This removes the impurities and once the impurities are melted away or separated, the steel is stronger. Crucibles are used for other metals such as aluminum, brass, bronze, and copper.

Your crucible is a potent literary device that strengthens and focuses the drama. Along with the antagonist, it will force the protagonist to  act in ways he or she normally wouldn’t act. Often his or her worst fears come into play. 
The crucible can be anything or place that creates unbearable pressures–a dysfunctional family, a hostage situation, a workplace, or the Titanic. Even if the crucible seems benign to outsiders, it must be a huge threat for the protagonist.

Keep writing, keep dreaming, have heart