Okay, here's what happened here: This chick right here, Naomi Misora, has been trying to join the Kira investigation. Of coarse Light doesnt want anyone getting in his way, so he writes down something like "kills herself in a secret area no one knows about". After the clock hits 40 seconds, there's nothing she can do. The only thing she can do is walk to her inevitable death. This is the reason people hate Light so much.