My Sister, the Serial Killer by Oyinkan Braithwaite — Summary & Review

Oyinkan Braithwaite’s debut novel My Sister, the Serial Killer throws you into the chaotic, vibrant streets of Lagos with a pair of sisters who couldn’t be more different—and yet are bound by blood and secrets. Korede, the older sister, is a nurse: practical, responsible, and painfully aware that she’s always been overshadowed by Ayoola, her younger sister’s effortless beauty and charm. But Ayoola has a habit that’s hard to ignore—she’s a serial killer. Not your run-of-the-mill villain, though. Her victims are exclusively her boyfriends, and the killings often happen in what she claims is self-defense. Korede is left to clean up the bloody messes, literally and figuratively, wrestling with the moral and emotional weight of protecting a sister who might be a danger to everyone around her.

The novel’s power lies not in a whodunit mystery—everyone knows Ayoola’s the killer—but in the simmering tension of Korede’s internal conflict. How far do you go to protect family? When does loyalty become complicity? Braithwaite doesn’t let you off the hook with easy answers. Korede’s narrative voice is sharp, deadpan, and quietly desperate, making her a deeply relatable guide through this darkly comic crime story.

Set against the backdrop of Lagos, the city itself almost feels like a character—its traffic jams, corrupt police, and unpredictable weather add texture and authenticity. The novel’s style is brisk and witty, blending crime thriller elements with a family drama and a touch of love story, thanks to Dr. Tade, a handsome doctor at Korede’s hospital who becomes the new object of Ayoola’s affection. His presence complicates Korede’s already fraught sense of duty and jealousy, adding another layer to the story’s simmering tension.

Braithwaite’s storytelling is economical but vivid, making the novel a page-turner that also invites reflection. She’s not interested in glamorizing violence or simplifying the characters into good and evil. Instead, she explores how trauma, beauty, and power play out in family dynamics. Ayoola’s beauty acts like armor and weapon, enabling her to manipulate situations and evade consequences, while Korede’s plainness and quiet competence keep her tethered to reality—and to the moral questions she can’t shake.

The novel’s themes hit close to home for anyone who’s ever felt trapped by family expectations or burdened by secrets they can’t share. It’s a story about the messy, complicated nature of love between siblings, about how trauma echoes across years, and how the line between protector and enabler can blur dangerously. The dark humor Braithwaite sprinkles throughout keeps the tone from becoming too grim, making the novel as entertaining as it is thought-provoking.

While the book’s brisk pace and sharp dialogue make it an engaging read, it’s not without its quirks. Some readers might find the characterization of Ayoola a bit one-note—her beauty and recklessness are emphasized, but her inner life remains somewhat opaque. Korede’s voice, while compelling, can feel a bit too deadpan at times, which might distance readers looking for emotional warmth. But these are minor gripes in a novel that’s otherwise a fresh, bold take on thriller fiction.

Ultimately, My Sister, the Serial Killer is a story about what family means when loyalty turns toxic and love becomes a kind of trap. It’s a reminder that sometimes the people closest to us are the ones we have to watch the most carefully. If you’re tired of predictable thrillers and want something that’s as smart as it is darkly funny, Braithwaite’s novel is worth the dive.