11 a.m. on a fall day in 2003, a crime scene analyst named Anna Cox was standing in the middle of a horrific crime scene inside of an apartment near Tampa, Florida. At her feet was a dead body in a pool of blood, and moving all around her were dozens of police officers and other investigators taking photos and collecting evidence. But none of those things or those other people stood out to Anna, because right now, the only thing she could think about was what she saw on the wall. She had never seen anything like this before... well, except for in movies, but no, sure enough, when she walked up to the wall, she realized that the thing that was on the wall was very real. And very, very disturbing.