My Sister, the Serial Killer was described by Deadline as a 'darkly comedic story, buzzed-about in publishing circles.' In her acknowledgements, Braithwaite thanks Ayọ̀bámi Adébáyọ̀ for adding the accents to the Yoruba language in the book. Korede fears that Tade will be Ayoola's next victim and must reckon with what she is willing to do for her sister.

However, upon meeting Ayoola, he is immediately enamored with her and they begin dating. She is in love with Tade, a kind, handsome doctor who does not notice her affection.

Korede feels unappreciated as she constantly dreads that they will be caught and that Ayoola will kill again, confiding in none but a comatose patient in the hospital she works at. Her practicality and concern keep Ayoola from acting suspiciously about her “missing” boyfriend, such as by posting to social media when she should be mourning. Like the previous times, Korede helps dispose of the body and clean away the evidence. For the third time in a row, Ayoola has stabbed her boyfriend to death, supposedly in self-defense. Ayoola is the more beautiful, favored sister, and possibly sociopathic. In Lagos, Nigeria, Korede is a nurse with a close relationship with her younger sister, Ayoola. Braithwaite's debut novel, it was originally published in Nigeria as an e-book entitled Thicker Than Water in 2017, before being released in the United States by Doubleday Books on November 20, 2018. My Sister, the Serial Killer is a 2018 thriller novel by Nigerian writer Oyinkan Braithwaite.

My sister the serial