June 4--Steampunk

Martha gaped at the painting. The birds weren't there yesterday. Neither were the breaks in the clouds.
Since the painting had arrived at the museum, it had shifted and changed nearly daily and oftentimes unperceptably. Martha had been drawn to the piece from day one as she prowled the building on her beat as a nighttime security guard.
At first, the city it depicted was light, the sun casting its rays on the tiny inhabitants. Clouds gradually built and the people thinned until the streets were deserted. Martha was concerned for them, then realized one night that perhaps she should be more concerned for herself. Paintings weren't supposed to change without the help of paintbrush and paint. Right?
Two days after the city became deserted and the sky had grown dark, he appeared. A disturbing figure wearing a ragged black coat, he stood on the pinnacle of the tallest, and closest, of the buildings. He leaned over the city, a satisfied leer crossing his face. Martha felt the ice chill down her spine when she first caught sight of him. Something was wrong in the oil paint city and she was a helpless witness to it.
The painting grew darker over the weeks, the light leeched from it. Martha felt compelled to check it at the beginning of her shifts. She had even started to volunteer for any extra shifts available so she could watch the shifting scene.