A recently divorced single mother, Yasuko Hanaoka, owns a restaurant and has a regular customer, Tetsuya Ishigami, a reclusive but brilliant mathematics teacher who lives next door. When Yasuko's abusive ex-husband is killed, Tetsuya offers his help to cover up the crime, plotting each step carefully. When the body is discovered, Yasuko becomes the prime suspect, and a detective seeks the help of Professor Manabu Yukawa, a physicist who initially refuses but later agrees to assist when he learns that Tetsuya, his former classmate, is involved.
Suspect X
The brilliant but eccentric physicist, Yukawa, engages in a mental showdown with detective Kaoru.
