>> the search expanded daily. at times it seemed the whole state of oregon was pitching in to find brooke. >> i have daughters this age and i want to help. >> more search teams, dozens of square miles. >> what is the geography like around here? where could someone have taken brooke? >> limitless. we're ten miles from interstate 5. we have a north-south highway running right through corvallis. we have an east-west highway running through corvallis. you could drive five miles from corvallis and be in a very remote area. >> in the deep woods? >> absolutely. >> that's right. >> but despite the odds, within days investigators were hot on someone's trail. coming up, a police search turns up a terrifying checklist and investigators wonder if it's the lead they have been waiting for. >> either someone is planning a very heinous mutilation, sexual assault crime and murder or it's a fantasy. >> when "bringing brooke home" continues.