The structure of The Big Clock gives the novel a fascinating complexity, as the author apparently identifies multiple characters as the protagonist. However, because George Stroud is the first-person narrator of more than half the chapters, it becomes clear that the reader should root for him, while his boss, Earl Janoth, is the antagonist. From Janoth himself, we learn that he is a killer.

As the novel opens, we learn that George is dissatisfied with his job at Janoth Enterprises, specifically at Crimeways magazine. With a wife and family to support, and increasingly thinking of himself as middle-aged, George thinks constantly about time and its inexorable march. This concern forms the metaphorical framework of the novel, as indicated by the title. Over breakfast one day, George muses:

Time.

One runs like a mouse up the old, slow pendulum of the big clock, time, scurries around and across its huge hands, strays inside through the intricate wheels and balances and springs of the inner mechanism, searching among the cobwebbed mazes of this machine with all its false exits and dangerous blind alleys and steep runways, natural traps and artificial baits, hunting for the true opening and the real prize.

Kenneth Fearing is known today as one of the masters of noir crime fiction. The dialogue is characteristic of the genre, including the euphemisms for sex that were necessary because of censorship of the publishing industry. When George decides to have an affair with Pauline Devos, a gorgeous blonde he had recently met, he takes her to a nearby apartment hotel after some drinks at a bar. The next morning, before they go separate ways, they get together again. George reminisces about the incident, including saying to Pauline,

I believe I said, "You're the last, final, beautiful, beautiful, ultimate enigma. Maybe you can't be solved."

And I think I looked at our great big gorgeous bed, soft and deep and wide. But it seemed a thousand miles away. I decided it was just too far. But that was all right. It was better than all right. It was perfect. It was just plain perfect.

I found out again why we are on this earth. I think.

As his own affair with Pauline advances, it is revealed that Pauline is the mistress of George’s big boss, Earl Janoth, the head of Janoth Enterprises. One night, George sees Pauline to her door, where Janoth meets her. The narrative switches to two chapters in Janoth’s voice. He sees her outside the building but only gets a glimpse of the man who had been with her. After they go up to her apartment, with Janoth in a jealous rage, they get into a shouting match. First he accuses her of having relationships with other women, and she makes a similar accusation about him and Steve, a man at work, calling him a homophobic slur. Janoth snaps:

I hit her again, and she kept talking with that awful voice of hers, and then I hit her twice more.

Then she was lying on the floor, quiet and a little twisted. I said: "There's a limit to this. A man can take just so much."

She didn't reply. She didn't move.

Janoth has killed her. He leaves her there, rationalizing that it was an accident, and goes to see Steve, to whom he confesses. Going over the details, they realize that the shadowy figure in the doorway is the loose end, and Steve helps him devise the plot to find and frame that man. The person Janoth designates to lead the search is George, and the rest of...