Nyx was an experimental biological weapon stored in Raccoon City. It was named after "Nyx", the Greek goddess of the night.
Research on Nyx took place in 1998 in Raccoon City. When a modified ε strain leaked into the city's drinking water in September 1998 during what would become known as the Raccoon City Destruction Incident, Nyx was in storage at an Umbrella-owned dockyard awaiting transport. By 1 October 1998, Umbrella HQ became aware of plans to destroy the city, and ordered its 2nd USS Squad to recover Nyx from the dockyards and evacuate it with a Chinook. The mission took serious casualties, and Captain Rodriguez betrayed the company and planned to keep the B.O.W. for himself. Umbrella HQ quickly ordered a UBCS team under Arnold to confront Captain Rodriguez, with the dockyard's manager, Tommy Neilson, in direct command. The attempt failed, and Captain Rodriguez flew out of the city with Nyx. What became of the B.O.W. is uncertain.[note 1]
↑As the Nyx crate does not appear in "Death's Door" and Tyrant R's relation to it is not addressed, it is assumed Nyx did not escape containment.