What breakthrough took place in apartment on a stormy November night Mary Frankenstein?

You're likely thinking of the novel "Frankenstein" by Mary Shelley, not "Mary Frankenstein."

There is no specific breakthrough that occurs in an apartment on a stormy November night in the novel. The creation of the monster takes place in a laboratory, not an apartment.

The story unfolds over several months, and Victor Frankenstein's work on creating the monster takes place in a secluded laboratory. The stormy night you're referring to might be a symbolic representation of the turbulent emotions and consequences of Victor's actions.

Let me know if you'd like to explore any other aspects of the story!