When Yuko Moriguchi's four-year-old daughter died in the middle school where she teaches, everyone thought it was a tragic accident. It's the last day of term, and Yuko's last day at work. She tells her students that she has resigned because of what happened - but not for the reasons they think. Her daughter didn't die in an accident. Her daughter was killed by two people in the class. And before she leaves, she has a lesson to teach... But revenge has a way of spinning out of control, and Yuko's last lecture is only the start of the story. In this bestselling Japanese thriller of love, despair and murder, everyone has a confession to make, and no one will escape unharmed.