A series of deadly incidents leads Georgia and her brother Shaun to discover efforts to undermine the campaign, linked to a larger conspiracy involving the undead.

McGuire's interests in horror movies and virology inspired her to write the book, but she struggled with the plot until a friend suggested using an election as a framing device.

The novel has been praised for its detailed worldbuilding, including the characters' awareness of previous zombie fiction—an element McGuire had found lacking in most horror works.

Most humans reside in tightly controlled safe zones, with rigorous blood testing and decontamination protocols used to prevent the spread of the live K-A virus.

After the inaction of traditional media during the Rising, blogs and other new media have taken over as the primary source of information and entertainment; bloggers are recognised as professional journalists, with individuals specialising and identifying as "Newsies" (objective, fact-based reporters), "Stewarts" ("who report opinion informed by fact"),[1] "Irwins" (named after Steve Irwin, who seek to educate and entertain by going out and "poking things with sticks"), "Aunties" (who share personal stories, recipes, and other content "to keep people happy and relaxed"), or "Fictionals" (fictional content and poetry creators).

Georgia, her brother Shaun (an Irwin), and their friend Georgette "Buffy" Meissonier (a Fictional and a technology guru), are selected to cover the presidential campaign of Senator Peter Ryman, a moderate Republican.

The next stage of the campaign is the Republican National Convention, where Ryman faces off against religious, right-wing Governor David Tate and sex-over-substance Congresswoman Kristen Wagman.

Ryman is selected as the Republican presidential candidate, but as this is announced, Georgia learns that a zombie outbreak occurred at the senator's horse ranch, and his eldest daughter is dead.

After administering a coup de grâce, Georgia calls for rescue, but the Centers for Disease Control (CDC) team drugs the surviving group members and takes them for testing.

The team finds evidence linking Tate to the attacks, along with hints of a broader conspiracy involving the CDC and other parties, but when Georgia confronts Ryman during an event in Sacramento, California, he is skeptical and sends them away to prepare to convince him with facts, otherwise he will fire them from the campaign.

[3] He singles out the level of detail in McGuire's worldbuilding for praise, and he observes that although most of the cast are stock characters, this is not a major obstacle in enjoying the book's narrative.

[3] Writing for Strange Horizons, Jonathan McCalmont praised Feed as a "delight", highlighting its overall structure, well written action and dialogue, and detailed worldbuilding.