The once-grand Cecil Hotel provides a nightmarish backdrop for the disappearance of Elisa Lam. Her final footage in an elevator triggers a viral hunt.

Web sleuths dissect Elisa's social media posts. A grisly discovery changes everything at the hotel already known as the Night Stalker's onetime lair.

The mystery deepens: Did a crime occur? The obsessed descend on the Cecil hoping to solve the case and tumble down the rabbit hole of conspiracy.