Part 36: Vertigo Secret 01
Featured music - "Techno Industry (Extended)" from the Descent II: the Infinite Abyss Redbook Soundtrack.
The first secret level of the Vertigo Series seems completely empty at first. The reactor is in the same room you begin the mine in and only a few robots are hanging around. By opening the wall by shooting the control panel, you can enter the room that appears to be fenced off. Nearly every weapon in the game can be found in this mine, so I highly recommend visiting it. Unlike most of the mines in Descent II, the Vertigo mines only have one entrance instead of two, so don't miss them.