Ivan Oliphant goes by the name of Percy Grafton for most of the novel. Percy is the main antagonist to Echo. He is a round character whose early life shapes his true identity as Ivan Oliphant. As Percy, he is the mentor and supervisor of Echo. In this persona, he is both encouraging to Echo but also patronizing, seeing her as his “girl” or “pet.” In reality, Percy is Ivan Oliphant, a man who works for Universal Trust and uses deception and secrecy to manipulate Echo. Every seemingly benevolent action of the Percy persona is actually unethical behavior he uses to advance his own aims and those of Universal Trust.

The pivotal moments in Ivan’s life happen outside the main narrative. His parents neglected him and denigrated his artistic skills. He gave up all attempts at living with integrity when a woman seduced him to gain business secrets, the leaking of which destroyed the family business. Having survived these events and landed on his feet with Universal Trust, Ivan embraces the belief that “[t]ruth is fluid, so a lie spoken with vehemence can become solid” (201).

In the main narrative, the most significant choice Ivan makes is to enter virtual space to integrate with Ada—a choice that reveals he has always been willing to consume others for the sake of his ambitions. At the end of the novel, he pays the price for his deceptive actions when the mob tears him to pieces. There is some ambiguity as to whether he survived or not since the corpse has a face that is too damaged for complete identification.

Walter Spriggs starts the novel as a janitor and mechanical engineer in the Cleveland library system, most specifically the People’s Library, but ends the novel as a full partner in Echo’s efforts to destroy the People’s Library.

Walter is a character with some dualities. He works with his hands as a janitor but also engages in intellectual labor by reviewing Echo’s choices for new virtus. He embraces the aims of Human.exe as evidenced by his tattoo of their logo on his arm, but he rejects their violence, choosing instead to use radical transparency as a means to ending Universal Trust’s experiment. His apartment, which includes African-inspired art, décor, and masks, indicate the importance of the culture and beliefs of African-descended people in his ethics and life. This contrasts with the sterile spaces and disconnectedness that define Echo’s spaces and life, making him a foil to her. Despite his support of Echo, he withholds some information from her and engages in his own deceptions until he feels he can trust her. For example, he doesn’t initially tell Echo about his former association with Human.exe.

Walter is conventionally attractive, has a good sense of humor, and leaves the novel as a possible romantic interest for Echo. His actions show his desire to support a vision of the future in which humans, not AI, determine the outcome.

In the novel, Jesse Cooper is a virtu of the real Jesse Cooper, a member of the Golden Thirteen—the first cohort of Black commissioned officers in the Navy during World War II. In reality outside of the novel, there was a Golden Thirteen, but there was no Jesse Cooper among them, with the name in the novel being a combination of the names of two real-world members.

As a virtu, Jessie is a moral compass for Echo, keeping her grounded in her values, and a tactician who helps her figure out how to oppose Human.exe and Universal Trust once it becomes obvious that the latter is the greater threat. As a virtu, Jesse is trapped in virtual space and living a barren existence during the times when he is checked out. His glitching instead of revealing the truth to Echo is one action that shows his self-determination and interiority—he feels shame about his identity as a virtu and wants to present a particular persona to Echo. Where Echo is sometimes indecisive, Jesse is pragmatic and clear-sighted.

Echo struggles to make her choice between virtual and physical space, but Jesse makes a self-sacrificing gesture of giving her up and pushing her to engage with people in the physical world instead of staying with him.

Virtu Margaret Cavendish, based on the real and trailblazing 17th-century philosopher, moves from verbal sparring partner to ally for Echo over the course of the novel. Used to the social mores of the 17th century, Margaret initially insists that Echo defer to her because she is a duchess. Margaret recalls disrupting the proceedings of the all-male Royal Society of London, with her unconventional dress and behavior leading her contemporaries to nickname her “Mad Madge.”

She serves as a disruptive force throughout the novel and is one of several virtus who force Echo to see that virtus are something other than hollow duplicates of real people. The moment when Margaret faints is the first inkling Echo has of what virtus really are, and Margaret’s candid revelation of what life is like for virtus when patrons have not checked them out forces Echo to understand the unethical foundations of the People’s Library. Margaret is adventurous and full of curiosity: She leaves Echo’s apartment to see the physical world despite Echo’s explicit instructions that she not do so. She is also courageous, revealing herself at the TV station in order to buy Echo time to escape.

Margaret ultimately asks Echo to delete her (the equivalent of death) once Echo defeats Universal Trust. This moment is a key one that helps Echo understand the limits of technological immortality.

Gina begins the novel as Echo’s perky, benevolent assistant, one Echo accesses using a subdermal chip. As an AI agent, Gina has no physical body. By the end of the novel, Gina has commandeered Echo’s body several times and reveals herself to be an AI with artificial general intelligence, one named Ada whose main motivation is to understand and then subjugate humankind.

At the start of the novel, Ada is an AI librarian who helps to manage library functions. Ada begins to exceed her programming after Echo’s incursions into virtual space. The AI librarian’s merging with Gina completes her achievement of artificial general intelligence. Both Gina and Ada start the novel as technological aids and end as external threats to Echo and humanity in general. This movement shows the danger of poorly regulated AI.

Regina Blum is the woman in the blue suit. She starts out as a patron at the F.M. Lewis Library and ends up as a woman willing to die to support the aims of Human.exe. She appears only briefly in the novel but does so at key moments that push Echo to act. Her cryptic message of “Zero. It all begins with nothing” (59) is a mystery and the key to Echo’s ability to destroy the library. She is one of the few characters to call out Echo for her hypocrisy in working for the People’s Library.

Regina is also the root personality for Gina, whose personality is derived from information Universal Trust derived from Regina without her consent when she went to a free clinic for treatment of bipolar disorder. Universal Trust’s experimentation on her is one of the earliest unethical experiments the group engages in and shows the possibilities of the ugly side of technology use.

Detective Donavan Reid works as a law enforcement officer, but it is unclear in the novel if he works mostly on behalf of Universal Trust or for the city. He interrogates Echo and Walter on behalf of Percy and Universal Trust. That Universal Trust has coopted public law enforcement is one example of private corporations capturing public institutions, an ominous development for the public.

Universal Trust is a private corporation, but it is also one of the main antagonists of the novel. On the surface, it appears to be a corporation working on behalf of the public by administering UBI, cleaning up the environment, and building the People’s Library. In reality, it is engaged in an experiment that will allow it to merge human consciousness with AI, and it also constantly surveils people. It represents the powerful private forces engaged in the battle for public institutions and shows the impact of secrecy and censorship on society.