Love on the Brain by Ali Hazelwood: Summary and Study Guide

⚠️ Spoiler Warning: This guide contains detailed spoilers for the entire novel. Proceed only if you've finished reading or are comfortable knowing the plot.

You can also jump to the ending explained page for a focused look at the finale.

For a quick recap, see the chapter summaries or the Q&A page.

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For essay ideas, check the essay prompts.

This guide is designed to help you understand the novel's plot, characters, themes, and symbols without spoiling the experience if you haven't read it yet.

If you're looking for a quick overview, the short summary below covers the essentials.

For a deeper dive, the full summary follows.

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Quick Facts

Short Summary

Love on the Brain follows Bee Königswasser, a neuroscientist at the NIH, who is unexpectedly chosen to lead a NASA neuroengineering project called BLINK. Her excitement turns to dread when she learns her co-lead is Levi Ward, her grad school nemesis. In Houston, Bee faces institutional sabotage, equipment delays, and a mysterious hacker, all while navigating her complicated feelings for Levi. As they work together, they uncover a conspiracy that threatens the project and Bee's career. Along the way, Bee confronts her fear of abandonment, discovers Levi's long-hidden love, and learns that science and love can coexist. The novel also critiques gender bias in STEM and the flaws of standardized testing, culminating in a satisfying resolution where Bee finds both professional success and a lasting relationship.

Full Summary

Love on the Brain opens with Bee Königswasser, a neuroscientist at the NIH, reflecting on Marie Curie's life and concluding that science is more reliable than love. She learns she has been selected as lead investigator for BLINK, a NASA neuroengineering project, and celebrates with colleagues. However, an email reveals her co-lead will be Levi Ward, her grad school nemesis. Bee recalls their history: Levi refused to compliment her before her first academic talk, avoided her, and told her fiancé Tim he could do better. She remembers the day Levi refused to collaborate with her in their advisor Sam Lee's office. As she packs for Houston, she finds the polka-dot dress she wore when Levi first dismissed her.

On the flight to Houston, Bee and her assistant Rocío discuss armadillos and leprosy. Bee reflects on her anonymous Twitter account @WhatWouldMarieDo, created after she faced harassment in grad school. She uses it to support women in STEM and often chats with another account, @Shmacademics. After landing, she settles into an apartment near the Johnson Space Center. At the Discovery Building, she meets astronaut Guy Kowalsky, who gives her a tour. During the tour, a kitten dislodges heavy equipment, and Levi shoves her out of the way, saving her. He checks her for injuries, and she loses consciousness.

On Monday, Bee wakes excited for BLINK. She wears her grandmother's ring and picks up Rocío. At NASA, Guy gives them a tour, showing empty rooms where equipment should have been delivered. Their shared office has only one computer instead of the five requested. Bee views the helmet prototype and points out that the output holes are too close together, which could cause hallucinations. Levi overhears her criticism. At a team meeting led by Boris Covington, Levi takes the only vegan donut and names The Empire Strikes Back as his favorite movie, matching Bee's answer. Afterward, Bee thanks Levi for saving her; he says he remembers her and asks about Tim. She apologizes for the angular gyrus comment. When she asks about equipment delivery, he says he'll keep her posted. He then tells her the building has a dress code that her piercings and hair violate; she challenges the double standard, but he insists.

On her second day, Bee and Rocío find their office badges malfunctioning. Guy lets them in and spends over an hour discussing brain stimulation research with Bee. He explains the equipment delay stems from an authorization problem. Over the following days, Bee's frustration grows as Levi remains unresponsive to her emails. She confronts him in the kitchen about the equipment; he says they are still working on it. Later, she overhears Levi chatting warmly with Rocío, though his demeanor turns cold when she enters. Rocío questions Bee about her history with Levi; Bee explains they were grad school peers who never got along. Rocío suggests asking @WhatWouldMarieDo on Twitter. That night, Bee drafts a tweet but doesn't send it, then calls her sister Reike, who advises a calm, firm conversation with Levi.

Bee's NIH supervisor Trevor calls to demand progress on BLINK, and she reports that her equipment and office access have not been delivered. Trevor reveals that BLINK is under high-level scrutiny and that weekly updates are now required, then threatens to replace her if she does not produce results. Bee phones the equipment supplier and learns that Levi canceled her TMS order the Friday before she arrived. Project manager Kaylee mentions a morning meeting with astronauts that Bee was never invited to attend. Bee confronts Levi in his office, demanding an explanation; he says the situation is complicated and asks for a few days, but she threatens to go over his head. She then encounters Rocío, who is distraught over low GRE scores, and offers to tutor her. When Bee finally reaches the office of Levi's superior, she hears Levi's voice inside.

Bee waits outside Boris's office and overhears Levi telling Boris that she needs full access and equipment and that she is the best neuroscientist for the project. Boris explains that BLINK will likely be delayed because NASA and NIH are fighting over patent ownership. Levi exits, sees Bee, and leads her to a picnic area, where he explains the political deadlock and warns that reporting to NIH would sour relations and delay the project further. Bee confronts him about his past coldness and avoidance, accusing him of despising her. Levi denies it, but Bee cries and walks away, saying she will tell NIH. At home, she messages Shmac, and they commiserate about work and quitting. Shmac mentions the woman he loves is still married.

Levi calls Bee early in the morning and asks her to meet him at Boris's office before a scheduled call with the NASA director. He tells her he wants her to stay and work on BLINK, and that no other neuroscientist could do the project. Bee agrees and arrives, following Levi's lead without knowing his plan. Levi shows Boris photos and blueprints of a similar neurostimulation helmet from MagTech, a Rotterdam-based company that supplies combat gadgets to armed forces. Bee observes that MagTech lacks a strong neuroscientist. Levi argues that BLINK must resume to beat MagTech to a working prototype and patent. Boris agrees to push the director for approval, warning there is no margin for error. Afterward, Bee and Levi apologize for their earlier conflict, and Levi insists he does not dislike her. Later, Levi texts that her equipment will arrive the next day and that she'll receive a NASA email account.

Chapter 8 opens with Bee reflecting on Marie Curie's friendship with engineer Hertha Ayrton and the press's harsh treatment of Curie's relationship with Paul Langevin. In a BLINK team meeting, Bee faces resistance from materials engineer Mark, who repeatedly rejects her proposal to reposition output channels. Levi arrives, supports her suggestions, and proposes changing the Kevlar blend, which the team reluctantly accepts. Later, Bee encounters the calico cat in the hallway, and Levi dismisses her claim. Walking home, Rocío confesses she hates Kaylee for trivial reasons. At home, Bee exchanges DMs with Shmac about his troubled relationship with a married woman. She then goes for a run at a nearby cemetery, gets locked inside after sundown, fails to reach Rocío, and calls Levi, who agrees to come rescue her.

Bee gets trapped on a cemetery wall while running; Levi arrives and helps her climb over with a ladder, catching her when she drops. He drives her home, and during the ride they discuss her running routine. She realizes she left her keys in the cemetery, so Levi offers her a place to stay for the night. She agrees, and they go to his house. She notices his garden and the clean, sparse interior. She asks about his family, and he explains he lives alone; Penny is not his daughter, and he is not married. He lends her clothes, she showers, and he prepares vegan tacos. They discover they are both vegan and share how they each became vegan. She thanks him for his hospitality, and he responds that it is not easy, but not for the reason she thinks.

Bee conducts brain stimulation tests on astronauts, including Guy, who replaces a participant with a seizure history. She demonstrates speech arrest and other effects, impressing the engineers. Later, Guy and Levi join her for lunch. Guy asks her on a date; Levi points to her grandmother's ring and claims she's married to Tim, and she goes along. She texts Reike about the lie, who warns it's easily disproven. Later, she meets Rocío for GRE tutoring; they argue over math. Kaylee joins, criticizes the GRE as biased, and offers to help Rocío. Kaylee also mentions that Levi changed Bee's status to team member so she can use the gym. Bee tweets about the GRE.

Bee and Levi work late alone in the engineering lab on a Friday night, collaborating on BLINK while Levi shares snacks. Bee asks for the newest blueprints; Levi says they're on the server, but Bee cannot find them. They bet: if Bee wins, Levi gives her his mug with the wording changed to 'neuroscientist'; if Levi wins, Bee must run a 5K in Houston with his training. Levi checks the server logs and finds the file was saved at 1:16 p.m. and moved to another folder at 4:23 p.m. He also notes other missing files, including Bee's frequencies list. Because the file was still on the server, Levi wins the bet. Boris arrives and orders them to attend the Human Brain Imaging conference in New Orleans that weekend, where MagTech will present their helmets. Levi walks Bee home, and she insists they not accuse the team without proof; Levi agrees.

Chapter 12 opens with Bee reflecting on how her tweet criticizing the GRE has grown into the #FairGraduateAdmissions movement, with media interviews and a joint essay with Shmac. Rocío announces she will stop preparing for the GRE in solidarity, crediting the movement to La Llorona rather than Bee. Bee and Shmac exchange texts in which Shmac confesses he is in love with a married woman and describes his intense, conflicted feelings; Bee responds sympathetically. Later, Lamar tells Bee he has updated the server to track file modifications at Levi's request after the missing-files issue. Bee confronts Levi about calling an engineering meeting without consulting her, arguing that co-leaders should agree before taking action. Levi defends his decision, and the argument grows tense before Levi ends it by stating he will pick her up at six for their trip to New Orleans, then leaves.

Bee and Levi drive to New Orleans for the HBI conference in silence after Bee refuses to greet him that morning. Levi apologizes for calling a meeting without her approval, admitting he was overly controlling about BLINK. During the drive, they discuss music, and Bee cries over a dead possum on the road. She tells Levi about her childhood: her parents died in a car accident when she was four, and she and her twin sister were raised by relatives across many countries before settling in the US. Levi explains he is the only civilian in his military family. At the conference, they meet acquaintances and plan their schedules. Levi mentions seeing Annie Johansson, and Bee spots Annie with Tim, which triggers a panic attack. Levi holds her as she reacts.

Bee wakes up in Levi's hotel room after fainting at the conference. She explains that she and Annie had a falling out over Tim, her ex-fiancé, who cheated on her with Annie. She reveals she never married Tim; the ring is her grandmother's. Levi says he and Tim no longer collaborate. Levi then takes her to the gym for a short treadmill run as part of 5K training. Later they go to a bar, where Levi tells her about his failed astronaut application due to height, and they discuss Guy and Schrödinger. They return to Bee's hotel room to watch Star Wars. Levi offers his hand to hold if she sees Annie and Tim again.

At a conference, Bee and Levi watch MagTech present a stimulation headgear that is slightly more advanced than their own NASA project, intensifying the race. After the presentation, they run into Sam, their former Ph.D. advisor, who invites them to her brunch and announces she is retiring. Bee agrees to attend despite Levi's reluctance. At the brunch, they encounter Tim, Bee's ex-fiancé, and Levi whispers something that leaves Tim visibly shaken. Later, Annie, Bee's former best friend who had an affair with Tim, approaches Bee in the restroom. Annie apologizes, explains her jealousy, and they reconcile, agreeing to try texting. Levi waits outside the bathroom, and they leave together.

During the drive back, Bee wakes from a nap and discusses BLINK with Levi. She gets upset over a dead raccoon, and Levi comforts her. She thanks him. Levi reveals he had always been attracted to her, but Tim warned him off, saying Bee found him unpleasant, so he avoided her. Boris Covington calls, asking them to come to the Discovery Building. There, they learn Rocío and Kaylee were caught having sex in Bee's office on security cameras. Boris handles it, and Bee and Levi talk to the women, who confirm it was consensual. Later, at Bee's apartment, she has a breakthrough idea for BLINK: bypassing the switchboard with separate circuits. Levi agrees it could work. They celebrate, and Bee asks if he will kiss her. He says he's afraid she won't go far enough. They kiss, but his phone rings. He answers a call from an ex and leaves. He returns for a goodbye kiss before departing.

Levi emails the team that he is taking personal time on Monday, crediting Bee for solving the hardware/software incompatibility issue and uploading three designs for the team to work on. Bee reflects on receiving credit and worries about Levi's unexplained absence. Rocío tells Bee she broke up with Alex and is now dating Kay, and plans to join the #FairGraduateAdmissions movement against the GRE. Bee finds an op-ed by STC vice president Benjamin Green attacking the movement and its influencers, including her own account, and sends it to Shmac. After a call with her sister Reike about the kiss, Levi arrives at Bee's door to return her backpack. He explains he was with Penny, the daughter of his late friend Peter Sullivan, who has epilepsy and needed medication adjustments. Peter died in a rock-climbing accident over a year ago, which Levi witnessed. Peter had convinced Levi to study engineering, and the Discovery Institute was renamed after him. Bee realizes why BLINK matters so much to.