Returning to London from France, Jake Donaghue learns that he and his friend, Finn, are being evicted from their free lodgings with their landlady, Madge. The two friends ask Dave Gellman, a teacher and philosopher, if they can stay with him, but Dave will only agree to allow Finn, and his and Jake’s baggage, to remain. Jake, Dave says snidely, has to make other arrangements with a lady friend. Finn suggests Jake ask Anna Quentin, Jake’s former girlfriend.

Though Jake has not seen or heard from Anna in years, he finds her easily once he starts looking. However, Anna will only let him stay one night, but suggests that he contact her sister, Sadie, who is looking for a caretaker for her place while she is away. Anna promises to contact Jake if she should need him.

The next day, Sadie agrees to let Jake watch her flat. She is especially concerned about the unwanted attentions of Hugo Belfounder, Jake’s former roommate. As roommates, the two had had many philosophical discussions, one of which Jake turned into a not-very-successful novel, The Silencer. In the novel, Jake had attempted to replicate one particular conversation with Hugo that dealt with language as the falsifier of experience. Jake feared his novel had betrayed Hugo’s ideas, so he ended their friendship by not meeting him one night as planned.

Reminded of all this, Jake returns to Madge’s to pick up her copy of The Silencer. Instead, he runs into Sammy Starfield, a bookie who thinks he has stolen Madge from Jake. He offers Jake money as compensation, but Jake refuses. Instead, he allows Sammy to bet money on the horses and, should they win, give the winnings to Jake.

On Tuesday, Jake reports to Sadie’s flat. As soon as she leaves, the phone rings. The caller is Hugo. Jake identifies himself, but Hugo hangs up. Jake decides to track Hugo down, even though Sadie had told him not to leave the flat. Jake finds that he is locked in. Luckily, Dave and Finn are walking down the street. They find Jake’s situation hilarious, but agree to get him out.

Finn picks the lock, and the three set off to find Hugo at the address Sadie had for him. There they find a note saying Hugo is at a nearby pub—but the note does not say which pub. They never find Hugo, but they do find Lefty Todd, leader of the Independent Socialists. Lefty and Jake have a political discussion until the pub closes. The group walks to the Thames River, and everyone but Dave strips for a swim. More drinking follows. Finally, Lefty leaves, and Finn passes out. Suddenly, Dave remembers that he has a note for Jake. The note, a couple days old now, is from Anna, asking Jake to see her at once. Afraid he is too late, Jake hurries to Anna’s mime theater.

Finding the theater empty, Jake spots a truck containing Anna’s things. A note attached to the neck of a rocking horse has Jake’s initial on it. Anna has had an offer and could wait no longer for Jake. At this upsetting news, Jake jumps from the truck and goes to Hyde Park, where he passes out in the grass.

Jake wakes up and returns to Sadie’s to retrieve her copy of his novel. There, he eavesdrops on Sadie and Sammy, who are plotting to sell Jake’s translation of novelist Jean Pierre’s book The Wooden Butterfly to Hugo’s film company. Jake decides he must go to Sammy’s flat to retrieve his translation. He calls Finn to help him. At Sammy’s place, they find Mister Mars, a movie dog, but not Jake’s translation. Jake decides to kidnap the dog to exchange him for the translation.

Finn returns to Dave’s place, and Jake sets off for the Bounty Belfounder film studio with Mister Mars, intending to find Hugo and warn him about Sadie and Sammy’s plot. Jake tricks his way into the well-guarded studio, where a labor rally led by Lefty Todd is in progress. Hugo is listening to Lefty and will not talk to Jake. A riot ensues, and the police show up. Worried that he will be arrested for stealing Mister Mars, Jake gets the dog to play dead and then uses the sympathy of the crowd for the poor limp dog and his owner to escape the scene.

Back at Dave’s flat, Jake finds several letters that have arrived for him. One contains money from Sammy for the bets he had placed a few days earlier. In the face of Sammy’s honorable act, Jake decides to contact him about the dog. However, Dave and Finn have already contacted Sammy to protect themselves from implication after seeing a picture of Jake and Mister Mars in a newspaper article about the riot. Dave accuses Jake of impulsive behavior but is interrupted when a telegram arrives for Jake from Madge with money and directions to meet her in Paris. Jake leaves Mister Mars with Dave and leaves immediately.

Once in Paris, Jake learns Madge has purchased all of Jean Pierre’s works for film, including the book that Sammy and Sadie had been eager to purchase after reading Jake’s translation. Madge wants to put Hugo’s film studio out of business and wants to hire Jake as her script writer. She claims to love Jake and says she wants to help him have what he has always wanted: “money for doing nothing.” Jake turns her down, and the offer leaves him depressed.

Outside, Jake gets caught up in national celebrations. Remembering the times he and Anna had shared in Paris, he suddenly thinks he sees her and then follows her. He finally catches up to the woman but finds she is not Anna after all. His entire life seems to be an illusion.

Back in London, Jake returns to Dave’s flat and goes to bed. In Jake’s absence, Finn has disappeared. Dave leaves Jake alone and even continues to take care of Mister Mars. Jake gets a job as an orderly at the hospital across the street from Dave’s place. One afternoon, Hugo is brought in my ambulance after getting hit on the head with a brick at a Lefty Todd rally. Jake believes that fate has brought Hugo to him and is determined to take the opportunity to talk to him.

From Hugo, Jake learns that Hugo loves Sadie but Sadie does not love him in return. Instead, it is Anna who loves Hugo. Also, though Sadie might love Jake, Jake loves Anna. Hugo declares the situation hopeless and demands that Jake help him escape immediately from the hospital. Jake warns Hugo about the plot on his studio, but Hugo does not care about that. He is giving up the studio to become a watchmaker, a job for which he says he has a talent. As they escape, Jake is spotted by his supervisor and knows he will be fired.

Once Jake and Hugo part ways, Jake realizes that everything has changed for him because all his assumptions have been false. Jake ends up back at Mrs. Tinckham’s shop with Mister Mars. Here he opens the mail that had again been collecting for him at Dave’s flat. The letters and packages help to clear things up for Jake, giving him an unobstructed view of reality. He now wants to buy Mister Mars and to get another a job in a hospital, a job that he can do well and a job he enjoys. He plans to write at night. Though Jake takes this as revelation, it is just what Dave has been telling him to do with his life.

Murdoch’s first novel and the only one that is clearly derivative, Under the Net was strongly influenced by French writer Raymond Queneau, to whom the book is dedicated, and author Samuel Beckett. The book is a combination of a picaresque novel and a philosophical enquiry. Although the work is not as tightly plotted and lacks the integration of her later novels, Under the Net exhibits many of the qualities that would become hallmarks of her style: a fast-moving story; precise, detailed descriptions of settings; strong use of contingency as a plot device; and philosophical deliberations about truth, love, and freedom.

Jake is a failed writer who earns money translating the works of a French writer. He is in love with Anna Quentin, a singer, and enormously influenced by Hugo Belfounder, a successful entrepreneur whom he meets at a clinic. There, they have serious dialogues about art and truth. When Jake is banished from his rooms, he tries to get in touch with Anna again. Through intricate and sometimes hilarious plot twists, he finds that Anna is in love with Hugo, and that Anna’s actress sister, Sadie, is in love with Jake. To complicate the plot further, Hugo is in love with Sadie.

This cast of main characters is rounded out by several minor characters who exhibit Murdoch’s remarkable inventiveness: Finn, Jake’s man Friday who eventually returns to Ireland; Lefty, a socialist organizer to whom Hugo donates a great deal of his wealth; Sammy Starfield, a self-made millionaire who used to be a bookie; and Mrs. Tinkham, the keeper of a dusty, dirty, corner newspaper shop where she sells ice cream, reads the merchandise, and offers a haven to drifters like Jake.

Jake starts out at the beginning of the book seeing everyone in relationship to himself. At the end, however, when he accepts that Anna will never be his, Anna exists for him as a separate being for the first time. He realizes that this, too, is a guise of love.