Korede lives with her sister and their mother in Lagos, Nigeria. Despite their shared blood, these sisters couldn't be any more different: Korede is sensible, a neat freak, somewhat unattractive, and helps save lives as a nurse at a local hospital. Ayoola is self-centered, a bit sloven, effortlessly gorgeous, and has a habit of killing her boyfriends. As the older sister, Korede takes it upon herself to protect Ayoola, doing her best to erase any evidence that could implicate them both.
After Ayoola kills her third boyfriend, Korede realizes that her sister technically qualifies as a serial killer. Despite this, Korede continues to stay silent, even while Ayoola's selfish behavior drives her up a wall. What keeps her sane is her periodic visits to Muhtar, a comatose patient to whom she vents about everything, and Tade, a handsome, kind-hearted doctor.
It isn't until Tade meets Ayoola and instantly becomes infatuated with her that Korede begins to act. Will Korede be able to convince him that Ayoola means him harm without revealing her darkest secret? Or will Tade become dead boyfriend number four?
My Sister, the Serial Killer is a 2018 psychological thriller by Oyinkan Braithwaite. Originally published online under the title Thicker than Water in 2017, My Sister is told in first person from Korede's perspective.
This novel provides examples of:
- Abusive Parents: Kehinde, Korede’s father. When he catches a little Ayoola playing with his prized knife, he flings her across the hallway. Later, when a boy from her school comes to visit Ayoola, he beats her brutally.
- Beauty Equals Goodness: How Tade perceives Ayoola.
- Beneath the Mask:
- Tade is handsome and friendly, if completely oblivious to Korede's feelings for him. Korede is heartbroken when he becomes interested in Ayoola, but then she understands that his interest in Ayoola is based on her looks.
- Korede herself. She is known as the responsible sister, but she helped her sister cover up for her murders, and she prepares herself for the possibility of having to deal with Mr. Muhtar now that he is awake. And her loyalty to her sister leads her to help put Tade in jail.
- Kehinde, Korede and Ayoola's father, comes across as a Cool Old Guy to the boy who visits Ayoola. In reality he is violent and abusive towards his wife and daughters.
- Elective Broken Language: A police officer stops Korede while she is driving the car she and Ayoola used to dispose of Femi's body. To dissuading the cop from taking a closer look and perhaps impounding the car, she tries talking to him in broken English (she is perfectly fluent), assuming he would be biased against her as an educated woman. She ends up having to bribe him for him to go away.
- Butt-Monkey: Korede's looks are often compared unfavorably to her beautiful sister's, to the point where people openly express their disbelief that they are sisters. Her feelings for Tade go unrequited and on top of that, he becomes besotted with Ayoola. And when she tries to warn him about what can happen if he dates Ayoola, he refuses to believe her.
- Conflicting Loyalty: Korede is protective of her sister, but she is also worried that Tade will become yet another one of her sister's victims.
- Converse with the Unconscious: Korede confides into Mr. Muhtar Yautai, who has been in a coma for five months at the start of the novel. He does wake up. And he remembers everything she told him.
- Disposing of a Body: How the sisters dispose of Femi's body:We take him to where we took the last one— over the bridge and into the water. At least he won't be lonely.
- The Dog Bites Back: Korede and Ayoola live in fear of their father. On the day he has his sister, Auntie Taiwo, come to the house to take a 14-year-old Ayoola to become the bride of a village chief, Korede decides they have had enough.
- Domestic Abuse: A flashback before the death of Korede's father has him bring another woman to the family home for the first time, even though his infidelity was well known both to her and her mother. Her mother for the first time rebels and gets in a tug-of-war with the other woman but Korede's father puts a stop to that by knocking her off her feet and hitting her in the face. The next day, the other woman is gone, and he is acting like nothing happened.
- Face of an Angel, Mind of a Demon: Every man who meets Ayoola is floored by her beauty but they don't bother to learn more about her.
- Freudian Excuse: Ayoola's father was abusive. When she was 14, he arranged to have her marry a rich village chief in exchange for a business contract. Korede killed him to prevent that.
- Gratuitous Yoruba: Expressions in Yoruba are dropped by people speaking in English, such as Jésù ṣàánú fún wa (literally: Jesus has Mercy on us]
- Foolish Sibling, Responsible Sibling: Ayoola is the former; Korede is the latter. She has to remind Ayoola NOT to post trivial things to her social media accounts when she is supposed to be worrying over her boyfriend (whom Ayoola killed) going missing.
- Head-Turning Beauty: Ayoola. And she is aware of it.
- In Love with Looks: Tade, Korede's crush ends up dating Ayoola, ignores Korede's warning that Ayoola is a Serial Killer of boyfriends, and even plans to propose to her. Ayoola dismisses her sister's heartbreak because Tade is just interested in her looks. Korede ends up realizing Ayoola is right.
- Karma Houdini: By the end of the book, Ayoola has killed four men, ruined the life of a fifth one, and introduces number six.
- Lingerie Scene: When the A/C is out of service at the family home, Ayoola hangs out in Korede's bed in a pink lace bra and black lace thong. According to Korede, she is "incapable of practical underwear".
- Love Triangle: Korede has a crush on Tade, a doctor at the hospital where she works. One day Ayoola comes to the hospital and meets Tade, who ends up smitten with her.
- Meaningful Name: In Yoruba, Korede means "Bringer of good fortune" and Ayoola means "Joy in Wealth". Without Korede being there, nobody would have protected Ayoola from her father's plans for her. As for Ayoola, she is somebody who enjoys luxury.
- Femi is a common Nigerian given name of Yoruba origin which means "love me". Femi is also a diminutive form of "Olufemi" which means "God loves me" ("Olu" means God in the Yoruba language).
- Never My Fault: Ayoola's attitude toward her boyfriends ending up dead. Korede finds her excuses very flimsy.
- Parental Obliviousness: Korede and Ayoola's mother never becomes aware of her younger daughter killing her boyfriends.
- The Reveal: How Korede's father died: Korede conspires with Ayoola to kill him after he agrees to let a village chief marry 14-year-old Ayoola in exchange for a contract.
- Sibling Triangle: Korede has a crush on Tade, a doctor at the hospital where she works. One day Ayoola comes to the hospital and meets Tade, who ends up smitten with her.
- Sleeps with Both Eyes Open: Yinka, one of the employees Korede oversees, is caught doing this at the reception desk. Korede wakes her up by slamming her clipboard on the desk.
- The Sociopath: Ayoola had to be instructed as to how to act as if she cares that her boyfriend is missing.
- Supermodel Strut: Proud Beauty Ayoola walks with a swing to her hips. At the hospital, Korede tries to do the same in hopes of impressing Tade. Instead, he asks if she is OK, as she is walking funny. Korede says it's just a pulled muscle.
- Wham Line: "Oh yes, I recall you saying that your sister is a serial killer." Mr. Muhtar, after he wakes up from his coma.
