I dreamed I was the last person on a hospital rooftop

It was raining, but not wet — more like static, like old TV snow. The ICU windows were all dark except one, where a nurse in a blue coat kept waving at me, though I couldn’t hear her. I stood there with my hands full of empty folders, each one labeled with a name I didn’t recognize. When I turned to leave, the roof wasn’t there anymore — just a long hallway lit by flickering fluorescents, and someone behind me said, 'You’re still here.' I didn’t answer. I never do.