When Lana Lee adds a catering service to her family’s noodle restaurant in the suburbs of Cleveland, Ohio, it’s not what she expected. At a birthday party for family friend Donna Feng, nanny Alice Kam is found dead in the outdoor swimming pool. It’s not an accident, as bruises are found around Alice’s neck and wrists. Lana attended the party as the caterer and heard the scream when a guest discovered Alice’s body floating in the pool.

Early in The Aosawa Murders, Riku Onda writes that “it’s impossible to ever really know the truth behind events,” setting the tone of the mystery surrounding a horrible mass murder in 1970s Japan in which seventeen people are poisoned by cyanide after drinking a toast with sake and soft drinks. What starts as a jovial birthday party for three generations of the Aosawa family ends in the family, their relatives, and friends dying in agony. The only survivor in the Aosawa family is Hisako, their blind teenage daughter.