Hal Jeffries’s isolation structures and drives the story. It gives rise to the voyeurism that guides each step of the plot. But ultimately, his isolation proves as fragile as glass, and he must contend with the consequences of his involvement in the affairs of others.

As the story begins, Jeff is physically confined to his apartment and cut off from the world around him. He is unable to interact with others and becomes increasingly obsessed with the lives of his neighbors. The obsession reinforces the reader’s sense of Jeff’s isolation as he watches the world go by without participating in it.

But while Jeff is frustrated by his isolation, he also revels in a sense of invulnerability that accompanies it. He feels in control at his seat by the window and retreats when there’s a possibility of being seen: “I withdrew several yards inside my room, to let it go safely by. I didn’t want him to think I was sitting there prying into his affairs” (17). The only gaze that seems to trouble him at the beginning of the story is the reader’s, and he tries to control even that. He says that readers could “mistake” his spying for the actions of a “Peeping Tom,” but “that wasn’t my fault, that wasn’t the idea” (15).

Jeff replaces real emotional connections and friendships with his voyeuristic projections. He alienates his friend Boyne, who grows concerned about Jeff’s paranoia and refusal to be persuaded by the apparent facts of the investigation. Jeff’s most intimate relationship is with his housekeeper Sam, but Jeff uses the man as a substitute pair of legs rather than as a confidant. His reckless pursuit of Lars Thorwald even leads him to endanger Sam’s life.

At the end of the short story, Jeff must confront his inability to remain separate from the world. His own rear window is penetrated as Thorwald spies on him. The murderer then mirrors Jeff/Sam’s physical intrusion but takes it to its violent extreme, bringing his gun to try to kill Jeff. Jeff is finally saved by the one friend he has. By involving Boyne, he sets in motion a chain of events that culminates in Boyne coming to the right conclusion at the right time and rushing to save Jeff’s life. Voyeuristic dynamics imperil him while healthy relationships are his literal salvation.

As Jeff discovers more of Thorwald’s crime, the tension between what is visible and what is hidden drives the mystery forward. Even before he begins investigating his neighbor, the story explores the relationship between the invisible, the unseen, the discovered, and the readily apparent. No matter how intimate the view, something remains out of sight.

Jeff’s perspective frames the mystery, but it is still limited, and Sam and Boyne supply important parts of the story. Parts of Thorwald’s apartment also elude him, and he fills in the details as best as he can. Sometimes these are trifling, obvious matters. In his kitchen, Thorwald reaches up and retrieves some objects. The narrator says, “Imagination had to supply a cabinet and a bottle” (23). Other times, Jeff guesses at important matters such as the location of Anna Thorwald’s body or Lars Thorwald’s actions in the dark. He is finally right about the central mystery, but he frequently missteps on his journey.

Woolrich still leaves gaps on the final page. Readers never get a conclusive summary of events. Jeff speculates about Thorwald’s motives and recreates the unseen event of the murder to the best of his ability, but it remains speculation: “Here’s the way I have it lined up, just in theory” (53). Several lines down, he again qualifies his tale: “I imagine—and remember, this is pure conjecture” (53).

If the events are unclear, the characters’ interiorities are even murkier. Other than the fact that he is visibly agitated, readers never know much about Thorwald’s frame of mind. Readers can’t tell anxiety from guilt. Nor do they have a handle on Thorwald’s motivations for killing his wife. Jeff raises multiple factors: frustration with her illness, a mistress, and financial troubles. There’s no way for readers to know which of these is correct or to uncover other, hidden elements of the unhappy marriage. Eventually, Thorwald’s interior life becomes so inscrutable to the narrator that he describes him as an inanimate object. When Boyne shoots him, and Thorwald falls from the roof, Jeff says, “He landed so far out he hit one of the projecting planks […] It bounced his body up, like a springboard. Then it landed again—for good. And that was all” (52). Thorwald starts these sentences as “he” but ends them as an “it” as the plank he hit on the way down. Even Jeff’s mind is a partial mystery to him. His instincts outrun his conscious, rational mind.