Vancouver student Elisa Lam was last heard from on January 31, 2013, after she checked into L.A.'s Cecil Hotel, a 600-room building with a history of scandal and tragedy. The next day, Elisa vanished. More than a week later came a grim discovery: Elisa's nude body floating in a rooftop water tank. The only clue was a disturbing surveillance video of Elisa, uploaded to YouTube in hopes of public assistance. The video soon went viral and opened up many questions. In this detailed investigation, journalist Jake Anderson sets out to answer them.