Lack of art!
He looked around, blinking unconsciously at the strain of standing up suddenly. Grabinski kept a neat room, even by the standards of the increasingly resource-starved lunar colonies. He had a bed, a perfunctory shower/bathroom combination stripped down to the fixtures, and a desk. There were no personal touches. Not even a toothbrush.
There was also no art. “Check me, Asenath,” Tobias wheezed. He could feel his entire upper respiratory system loosening up under the sudden humidity, only it wasn’t actually pleasant. “No sign of Grabinski drawing on the walls themselves, right?”
Correct, Commander. Do you see the discolorations on the wall?
“Yeah. Grabinski must have been hoarding sticky tape.” He bit down on the sudden spike of white-hot, murderous rage the thought had triggered. “Or maybe he had something else. Anyway, either he didn’t do any painting here, or he took it with him when he left. When was the last time he was here?”