>> text messages, security monitors, surveillance videos. where their sons that she was trapped, reaching out for help? >> one of the things about, this is that didn't make sense. >> moment by moment -- >> dateline was there for every turn. >> look, there's blood wiped across. hear >> was she missing or murdered? was this the key? >> i will take her life and hers. >> a threat, a voice seething with hate and rage. >> you deserve to die for your lies. it's your last and final warning. >> what's happened to michelle? >> this case is not going to be over until we get her home. >> i'm lester holt, and this is dateline. they are watching us. they know where we are.