When an unidentified hiker is found deceased in the Florida wilderness, authorities release a sketch. Multiple hikers call in claiming to have met the man. There's only one problem – he never told them his name. It would take two years, thousands of devoted internet sleuths, and a miracle of science to identify him, and that's when the trouble really starts.

An unidentified man posts a live feed on social media showing that he has kidnapped two strangers and intends to kill one before the day is out. His intention is to hold a capital 'trial' online. As the authorities recognize what's happening, it becomes apparent that the online public is going to act as judge and jury.