Dark and Miss Hinch capture the timeless struggle between good and evil. The stereotypical plucky detective and writer chases down known criminals using her cleverness. She makes a name for herself in a male-dominated profession even before women have the right to vote. She is also single and lives independently, according to one of the train passengers. Jessie “was a ‘crime expert’ to be taken seriously, it seemed—no mere office-desk sleuth, but an actual performer with, unexpectedly enough, a somewhat formidable list of notches on her gun” (560). She has a reputation for taking down criminal women, and it is asserted that “the woman doesn’t live who is clever enough to hoodwink Jessie Dark” (562). She is a respectable woman who takes pride in taking down other women who refuse to follow the law.

Conversely, Miss Hinch embodies the fallen woman. She is an unmarried actress carrying on an affair with a man of status, and she murders him rather than allowing him to marry his betrothed and maintain the image of respectability with another woman. Her talent even terrifies her friends and dinner guests, who must beg her to stop as they are “frightened out of their lives […with…] the terrible faces she could make” (561). Miss Hinch is described as a creature of the dark, seedy underbelly of the city, a place into which she disappears after committing her heinous crime. A newspaper’s headline claims that the “Earth opened and swallowed Miss Hinch” (560). Even her chosen method of escape, the subway, lies in the dark tunnels under the earth, rather than above ground in visible spaces.

The battle of good and evil goes on as the two women struggle against one another. Dark uses her skill to track and identify Miss Hinch, whose suspicions lead her to mistrust the kindly elderly woman. Miss Hinch catches Dark in a lie about her whereabouts before their meeting, but then wonders if “his silence had not been an error of judgment” (563). When Dark senses that she set her prey on edge, she leads the disguised murderer out above ground and into a restaurant she suggests, taking control of the situation. Dark leaves clues for the train employees and police to follow and even waylays Miss Hinch as she makes a desperate play for escape.

At this turn, evil seems to take the upper hand. Miss Hinch/the clergyman “looked full at the woman, and she saw there was a smile on his face” (566). Dark catches Miss Hinch as she runs, but this is also the moment when her prey decides to kill her. Miss Hinch leads Dark back down beneath the earth, carefully laying the trap that will allow her to escape. Dark tries to slow Miss Hinch down, but she is pulled inexorably to the platform. As the roaring train approaches, Dark’s foot “slipped upon the treacherous ice—or it may have tripped on the stout cane when the clergyman suddenly shifted its position” (568). Miss Hinch led her pursuer into darkness and to death, yet in the final plot twist, the author allows Dark to retain hero status, casting her as having reached out beyond death to catch her final killer.