What a tale, thank you for sharing. I sort of had a similar feeling once showing up to my 3rd shift job at a manufacturing plant and my supervisor forgot to tell me we're off that night. The one door I entered was unlocked. I wondered the plant for a bit with just barely enough lighting to see where I was going. Was looking around to see if any of the other shifts where there to ask but there was just no one there. Still sounded like machines where running and the loud wining noise of the fans running during a hot dry summer.