The "Young Man" of the title works in a chemical factory, and is very fond of the novel Moby Dick by Herman Melville. His roommate also works at the factory as a chemical engineer. The lad has been told many stories about the older man's former mistress, an ambitious and selfish woman by all accounts. When the two learn that she plans to look the engineer up, coming all the way from Prague to do so, it provokes a lot of interest. It turns out that she is seeking her old lover's help in developing a process for manufacturing a pharmaceutical base product. She has been unable to get support for her efforts back in Prague. Reluctantly, the engineer is persuaded to help her, and the young man is drawn to the woman.