A Crack of Light

I saw a gap... just a tiny sliver of light under the big wooden door at the end of the hall. I ran over, tapping the cold baseboard with both hands, trying to peek through. Is it... an exit? But when I pushed against the heavy panel, it didn't budge at all. Just a gentle draft whistling through the crack, rustling the fringe of the rug. I backed up a few steps, keeping my eyes glued to that bright line just in case.