My Sister, the Serial Killer is the debut novel of a Nigerian-British writer Oyinkan Braithwaite. The story is multi-faceted and cannot simply be classified as a murder mystery. It has been met with great reviews and received praise since its publication in 2019. 
The two main characters, Korede and Ayoola are sisters that are opposite in many ways. Ayoola is many things: a joyful and beautiful woman, her mother’s favourite child, and the last loves and the murderers of the three last men she has dated. Korede is the first-born daughter, who is average looking on every level. But she is an appreciated nurse and an A-class cleaner, who feels obliged to help her little sister get away with three homicides. Rather than detailing each murder, the author puts more focus on Korede’s swirling emotions and the relations between the two sisters. As the author progresses the story through Korede’s perspective, her emotion is uncoded in detail: confusion, fear, pain and frustration toward Ayoola’s romantic relations with her secret love Tade and the repetitive killing of boyfriends. Still, her memory of abuse   father is deeply engraved in Korede’s mind, and she still considers herself  her little sister’s only protector . 
Throughout the story, the author demonstrates that lookism provides characters with particular advantages. For instance, a character in the book is mostly treated nicely based on her attractiveness. Further, the character is presumed innocent, harmless, and honest by most other characters in the book when, in fact, she continuously lies to them to hide her dark secret.
Unique to this genre, this book introduces you to a new type of serial killer and accomplice that you will struggle to figure out. It certainly is distant from the didactic novels that punish evil in the end. Readers can get an insight that preconception and prejudice can blur the judgment and could risk lives of the innocent.