B. Lippincott & Co.[1] The shortest of Pynchon's novels, the plot follows Oedipa Maas, a young Californian woman who begins to embrace a conspiracy theory as she possibly unearths a centuries-old feud between two mail distribution companies.

One day, Oedipa learns of the death of an ex-lover, Pierce Inverarity, an incredibly wealthy and powerful real-estate mogul from the Los Angeles area, who has nominated her as the executor of his estate.

It emerges that Inverarity had Mafia connections, illicitly attempting to sell the bones of forgotten U.S. World War II soldiers for use as charcoal to a cigarette company.

After the show, Oedipa approaches the play's director and star, Randolph Driblette, who deflects her questions about the mention of the unusual name.

She researches an older censored edition of The Courier's Tragedy, which confirms that Driblette indeed made a conscious choice to insert the "Tristero" line.

Finally, a nameless man at a gay bar tells her that the symbol simply represents an anonymous support group for people with broken hearts.

Fearing for her sanity, Oedipa makes an impromptu visit to Dr. Hilarius, only to find him having lost his own mind, firing a gun randomly and raving madly about his days as a Nazi medical intern at Buchenwald.

Oedipa consults an English professor about The Courier's Tragedy, learns that Randolph Driblette has mysteriously committed suicide, and is left pondering whether Trystero is simply a prolonged hallucination, a historical plot, or an elaborate practical joke that Inverarity arranged for her before his death.

[5] In a positive The New York Times review, Richard Poirier wrote "Pynchon's technical virtuosity, his adaptations of the apocalyptic-satiric modes of Melville, Conrad, and Joyce, of Faulkner, Nathanael West, and Nabokov, the saturnalian inventiveness he shares with contemporaries like John Barth and Joseph Heller, his security with philosophical and psychological concepts, his anthropological intimacy with the off-beat – these evidences of extraordinary talent in the first novel continue to display themselves in the second".

[11][12] This alludes to a famous retort of Maxwell's demon by Szilard and Brillouin which sought to establish congruence between entropy in information theory and thermodynamics.

[14][13] Oedipa's role within The Crying of Lot 49 can be likened to Maxwell's demon—a force which seeks to reverse the flow of entropy on the town of San Narciso.

[14] Just as the demon is hypothesized to sort unpredictable, random molecules to create order from disorder, Oedipa seeks to make sense of the mystery of Trystero.

[14] Pynchon devotes a significant part of the book to a play-within-a-book, a detailed description of a performance of an imaginary Jacobean revenge play, involving intrigues between Thurn und Taxis and Trystero.

[15] Like "The Mousetrap", based on "The Murder of Gonzago" that William Shakespeare placed within Hamlet, the events and atmosphere of The Courier's Tragedy (by the fictional Richard Wharfinger) mirror those transpiring around them.

Most prominent are the Paranoids, a band composed of cheerful marijuana smokers whose lead singer, Miles, is a high-school dropout described as having a "Beatle haircut".

The Paranoids all speak with American accents but sing in English ones; at one point, a guitar player is forced to relinquish control of a car to his girlfriend because he cannot see through his hair.

Late in the novel, Oedipa's husband, Mucho Maas, a disc jockey at Kinneret radio station KCUF, describes his experience of discovering the Beatles.

At one point he expresses his angst in song: Early in The Crying of Lot 49, Oedipa recalls a trip to an art museum in Mexico with Inverarity, during which she encountered a painting, Bordando el Manto Terrestre ("Embroidering the Earth’s Mantle") by Remedios Varo.

Oedipa's reaction to the tapestry gives us some insight into her difficulty in determining what is real and what is a fiction created by Inverarity for her benefit, She had looked down at her feet and known, then, because of a painting, that what she stood on had only been woven together a couple thousand miles away in her own tower, was only by accident known as Mexico, and so Pierce had taken her away from nothing, there'd been no escape.